Question 78. The Soul's Pre-Intellective Capacities
Next we must consider the soul's specific capacities. Now a theologian, in his investigations, has to be concerned with making a specific inquiry only into the intellective and appetitive capacities; it is here that the virtues are found. But because a cognition of these capacities depends in a certain way on the others, our consideration of the soul's specific capacities will have three parts. For we must consider
· first, the capacities that come before intellect [Q78];
· second, the intellective capacities [Q79];
· third, the appetitive capacities [QQ80-83].
As regards the first there are four subjects of inquiry:
a1. The kinds of capacities belonging to the soul.
a2. The species of the vegetative part.
a3. The external senses.
a4. The internal senses.
Article 1. The kinds of capacities belonging to the soul
It seems that we should not distinguish five kinds of capacities belonging to the soul -- vegetative, sensory, appetitive, locomotive, and intellective:
1. The soul's capacities are said to be its parts. But only three parts of the soul are generally assigned by everyone: the vegetative soul, the sensory soul, and the rational soul. Therefore there are only three kinds of capacities belonging to the soul, not five.
2. The soul's capacities are the bases for the functions associated with life. But a thing is said to be living in four ways. For the Philosopher says in De anima II [413a22-25] that "because living is spoken of in many ways, we say that a thing lives even if only one of these is present: intellect, sense, local movement and rest, and finally the movement involved in feeding, decay, and growth." There are, then, only four kinds of capacities belonging to the soul -- leaving out the appetitive.
3. No specific kind of soul should be devoted to that which is common to all capacities. But appetite belongs to each of the soul's capacities. For sight has an appetite for an agreeable visible object; so it is said in Ecclesiasticus 40.22 that the eye will desire grace and beauty and, beyond this, green sown fields. Every other capacity, for the same reason, desires an object agreeable to it. Therefore appetite should not be held to be a single specific kind among the soul's capacities.
4. The basis of movement in animals is either sense, intellect, or appetite, as is said in De anima III [433a9-10]. Therefore the motive power should not be held to be a specific kind of soul beyond the ones just listed.
On the contrary. The Philosopher says in De anima II [414a31-32], "we say that these capacities are the vegetative, sensory, appetitive, locomotive, and intellective."
Reply. There are five kinds of capacities belonging to the soul, as just listed. Three [of these] are called souls, whereas four are called modes of living.
The reason for this discrepancy is that different souls are distinguished° in keeping with the different ways a soul's operation surpasses the operation of corporeal nature. For all corporeal nature lies under the soul, and is related to it as its matter and instrument.° So there is one operation of the soul that exceeds corporeal nature to such an extent that it is not even exercised through a corporeal organ. This is the operation of the rational soul. There is another operation of the soul, below that one, which is brought about through a corporeal organ, but not through any corporeal quality. This is the operation of the sensory soul. For even if hot and cold, wet and dry, and other such corporeal qualities are required for a sense to operate, still this is not in such a way that the sensory soul's operation gets carried out mediated by the power of such qualities; they are instead required only for the proper disposition of the organ. Finally, the lowest of the soul's operations is that which is brought about both through a corporeal organ and by the power of a corporeal quality.° Still, it surpasses the operation of corporeal nature, because the motions of bodies come from an external source, whereas operations of this sort come from an internal source. (For this is common to all the soul's operations; for everything with a soul moves itself in some way.) The operation of the vegetative soul is of this lowest kind. For digestion and the operations that follow, such as the absorption of food and the release of waste, are brought about instrumentally through the action of heat, as is said in De anima II [416b27-29].
The kinds of capacities belonging to the soul are distinguished in terms of their objects. For to the extent that a capacity is loftier, to that extent it is concerned with a more universal object, as was said above [77.3 ad 4]. But there are three levels at which the objects of the soul's operations can be considered. For the object of one capacity of the soul is only the body united with the soul. This kind of capacity of the soul is called the vegetative; for the vegetative capacity acts only on the body to which the soul is united. There is another kind of capacity belonging to the soul, a kind concerned with a more universal object -- namely, with every sensible body, and not only with the body united to the soul. There is still another kind of capacity belonging to the soul, one that is concerned with a still more universal object -- namely, not only with sensible bodies, but universally with all being.
From this it is clear that these latter two kinds of capacities of the soul have an operation that concerns not only a connected object, but also an extrinsic one. But because that which operates must somehow be connected to the object it operates on, an extrinsic thing that is the object of an operation of the soul must be related to the soul in two respects.
· First, inasmuch as it is suited to be connected to the soul, and to be in the soul through its likeness. There are, in this respect, two kinds of capacities: the sensory, which concerns a less common object, a sensory body, and the intellective, which concerns the most common of objects, universal being.
· Second, inasmuch as the soul is inclined and tends toward an external thing. And in regard to this relationship as well, there are two kinds of capacities belonging to the soul: One is the appetitive, in virtue of which the soul is related to an extrinsic thing as to its end, which comes first in its intention.° The other is the locomotive, inasmuch as the soul is related to an external thing as to the endpoint of its operation and movement. For every animal that moves does so in order to pursue something desired and intended.
Modes of living are distinguished in terms of the grades of living beings. For there are some living beings that have only the vegetative power, as plants do. Then there are some that have the sensory power as well as the vegetative, but not the locomotive. (This is the case for immobile animals like shellfish.) Some, beyond this, have locomotion, as do complete animals, which need many things for their lives and so need to move so that they can search out the necessities of life that are not placed right at hand. Finally, there are some living beings in which, along with these, there is the intellective power -- namely, human beings. The appetitive does not make up a grade of living beings, because whatever has sense also has appetite, as is said in De anima II [414b1].
This solves the first two objections.
Ad 3. Natural appetite is the inclination of any given thing, of its own nature, for some thing. Thus any capacity desires, by natural appetite, that which is agreeable to it. But animal appetite is the result of a form that has been apprehended. This sort of appetite requires a specific capacity of the soul: the apprehension alone is not enough. For one has an appetite for a thing as that thing is in its nature, whereas the thing is not in an apprehensive power in virtue of its nature, but in virtue of its likeness. It is clear, then, that sight has a natural appetite for a visible object only as regards its act -- namely, as regards seeing. The animal, on the other hand, has an appetite for the thing seen through its appetitive power -- not only as regards seeing, but also as regards other uses. However, if the soul were to have no need for the things perceived by the senses, except for the sake of the actions of those senses (namely, so that it would sense them), then we would not have to posit the appetitive as a specific kind among the soul's capacities. For then the natural appetite of the capacities would be adequate.
Ad 4. Although sense and appetite are the bases of movement in complete animals, nevertheless these powers, considered as such, are not sufficient for producing movement unless another power is added to them. For there is sense and appetite in immobile animals, and yet they lack motive power. This motive power is not only in sense and appetite so as to command movement, but also in the relevant parts of the body, so that they are ready to obey the appetite of the soul that produces the movement. An indication of this is that when one's limbs are taken out of their natural disposition, they do not obey the appetite for movement.°
Article 2. The capacities of the vegetative part
It seems that the parts of the vegetative soul -- the powers for nutrition, growth, and generation -- are incorrectly set out:
1. Powers of this sort are said to be natural. But the soul's capacities are above the natural powers. Therefore powers of this sort should not be posited as capacities of the soul.
2. That which is common to the living and the nonliving should not be counted as one of the soul's capacities. But generation is common to all generable and corruptible things, both living and nonliving. Therefore the generative power should not be posited as a capacity of the soul.
3. The soul is more powerful than corporeal nature. But corporeal nature, through the same active power, gives [a thing] both its species and its proper size. Therefore, a fortiori, so does the soul. Therefore the soul's capacity for growth is no different than its capacity for generation.
4. Each thing is maintained in existence through that through which it has existence. But it is through the generative capacity that a living thing acquires its existence. Therefore a living thing is maintained through that same capacity. But it is the nutritive power that is directed at the maintenance of a living thing, as is said in De anima II [416b18], since it is "a capacity capable of preserving that which receives it." Therefore the nutritive capacity should not be distinguished from the generative.
On the contrary. The Philosopher says in De anima II that the functions of this soul are to generate [415a22-26], to make use of food [415b23-28], and also growth [413a25-31].
Reply. There are three capacities of the vegetative part. For, as was said [78.1cxx], the vegetative has for an object the body itself that lives through the soul. With respect to this body, three operations of the soul are necessary:
· one through which it acquires existence; the generative capacity is directed at this;
· a second through which the living body acquires the appropriate size; the power for growth is directed at this;
· a third through which the body of the living thing is preserved, as regards both existence and proper size; the nutritive power is directed at this.
There is, however, a notable difference among these capacities. For the capacities for nutrition and growth have their effect on that in which they exist, because the body united to the soul grows and is maintained through the powers for growth and nutrition that are in that same soul. The generative power, in contrast, has its effect not on the same body but on another one: for nothing generates itself. And so the generative power in a certain way approaches the stature of the sensory soul, which has its operation on external things, though in a more excellent and universal way. For the highest of lower natures touches the lowest of those higher,° as Dionysius makes clear in Divine Names 7.3. Consequently, the generative capacity is the one that is final, chief, and most complete of the three, as is said in De anima II. For it belongs to that which is already complete "to produce another such as it is" [415a26-29]. Also, the capacities for growth and nutrition serve the generative capacity, whereas the nutritive capacity serves the capacity for growth.
Ad 1. Powers of this sort are called natural both because they have an effect like that of nature, which also supplies existence, size, and maintenance (though these powers have this effect in a loftier way), and because these powers carry out their actions instrumentally through the active and passive qualities, which are the principles of natural actions.°
Ad 2. In the case of things without souls, generation comes entirely from without. But the generation of living things occurs in a loftier way, through something that belongs to the living thing, its seed, which contains the basis for forming the body. Consequently, a living thing must have a capacity that prepares this seed -- and this is its generative power.
Ad 3. Because the generation of living things comes from a seed, an animal must be small in size at the start. For this reason it is necessary that the animal have a capacity of the soul through which it reaches the proper size. A body without a soul, in contrast, is generated from determinate matter by an outside agent, and so it receives its species and its size all at once, in keeping with the state of its matter.
Ad 4. As was already said [78.1cxx], the operation of the vegetative principle is completed through heat, which consumes moisture. So in order to restore the lost moisture, it is necessary for it to have a nutritive capacity, through which food is converted into the body's substance. This is also necessary for the action of the powers for growth and generation.
Article 3. The external senses
It seems that the five external senses are incorrectly distinguished:°
1. The senses cognize accidents. But there are many kinds of accidents. Therefore, since capacities are distinguished by their objects, it seems that the senses are multiplied according to how many kinds of accidents there are.
2. Size, shape, and others that are called common sensibles are not sensible per accidens, but are divided against these in De anima II [418a8-20]. It is the difference in per se objects, however, that differentiates capacities. Now size and shape are more different from color than sound is. Therefore it seems that there should be a different sensory capacity for cognizing size or shape, much more than there should be for color and sound.
3. There is a single sense for a single contrary pairing -- sight, for instance, has to do with white and black. But touch cognizes many contrary pairings, such as hot and cold, wet and dry, etc. Therefore it is not a single sense, but many. Therefore there are more than five senses.
4. Species is not divided against genus. But taste is a kind of touch. Therefore it should not be posited as a different sense from touch.
On the contrary. The Philosopher says in De anima III [424b22-425b3] that there is no other sense beyond the five.
Reply. Some have wanted to derive an account of the distinction and the number of the external senses from [a] their organs, in which one of the elements is predominant (water, air, etc.). Others have looked to [b] the medium, either connected or extrinsic (the latter being either air or water, or both).° Still others have looked to [c] the differing nature of the sensible qualities, according to whether it is the quality of a simple body or the result of a mixture.°
None of these is correct. For [a] capacities do not exist on account of organs, but organs on account of capacities. As a result, the different capacities do not exist on account of the different organs; instead, nature has established this difference in organs so as to match with the difference in capacities. Likewise, [b] nature has assigned the different media to the different senses according to what was right for the acts of the capacities. And [c] it belongs not to sense but to intellect to cognize the natures of sensible qualities.
We should, then, derive an account of the number and distinction of the external senses on the basis of what pertains to the senses properly and per se. The senses, however, are passive capacities,° naturally suited to be impressed upon by an external sensible quality. Therefore the external thing making the impression is what the senses perceive per se,° and the sensory powers are distinguished in terms of how that cause differs.
There are, however, two kinds of impressions, one natural and the other spiritual:°
· A natural impression occurs inasmuch as the form of what does the impressing is received in the thing impressed upon according to its natural existence, as heat is received in the thing being heated.
· A spiritual impression occurs inasmuch as the form of what does the impressing is received in the thing impressed upon according to its spiritual existence, as the form of color is received in the pupil, which is not by this made colored.
Sensory operation requires a spiritual impression through which an intention of the sensible form is produced in the organ of sense. Otherwise, if an entirely natural impression were to suffice for sensation, then all natural bodies would sense when they are altered.° But in certain senses, like sight, there is a spiritual impression only. In others there is a natural impression along with the spiritual impression -- either on the part of the object alone, or also on the part of the organ.
· On the part of the object, a natural transformation in location occurs in the case of sound (the object of hearing). For sound is caused by the air's being struck and put in motion. In the case of odor (the object of smell), this transformation occurs by alteration. For a body must in some way be altered by heat if it is to give rise to an odor.
· On the part of the organ, there a natural impression in the cases of touch and taste: the hand, when it touches things that are hot, is made hot too, and the tongue is made moist by the moisture of flavors. In contrast, the organ of smell or hearing receives no natural impression while sensing, except incidentally.
Sight, because it occurs without any natural impression to either the organ or the object, is the most spiritual and perfect of all the senses, and the most common.° After this comes hearing and then smell, the senses that involve a natural impression on the part of their object. (Local motion is more perfect and naturally prior to the motion of alteration, as is established in Physics VIII [260a26-b7].) Touch and taste, finally, are the most material (the distinction between them will be discussed shortly [ad 3-4]). This is why the other three senses do not work through a connected medium; it is so that no natural transformation reaches their organs, as happens in the case of these two senses.
Ad 1. Not all accidents have the power in their own right to make an impression. This is the case only for qualities of the third species,° in virtue of which alteration takes place. As a result, only qualities of this sort are the objects of the senses. For as is said in Physics VII [244b5-45a10], the same things alter the senses that alter inanimate bodies.
Ad 2. Size, shape, and the like, which are called common sensibles, fall in between per accidens sensibles and proper sensibles. These last are the objects of the senses: for the proper sensibles make an impression on the senses primarily and per se, since these are the qualities that produce alterations. All common sensibles, in contrast, are reduced to quantity:° It is clear that both size and number are kinds of quantity, whereas shape is the quality that encompasses quantity. (For shape is defined as the limitation of size.) Further, motion and rest are sensed inasmuch as the subject stands in either one or several ways relative to [a] the subject's size or [b] the size of the local distance (as regards growth and local motion [respectively]) or else relative to [c] its sensible qualities (in the case of alteration). To sense motion and rest is therefore in a way to sense one thing and many.° Quantity, however, is the proximate subject of those qualities that produce alteration, as a surface is the subject of a color. And so the common sensibles do not move the senses primarily and per se, but on account of a sensible quality, as a surface does on account of its color.
Neither, on the other hand, are they sensible per accidens, since the common sensibles make a difference in the impression received by the senses.° For a large surface makes a different kind of impression on the senses than does a small surface: even whiteness itself, after all, is said to be large or small,° and so is differentiated in virtue of its proper subject.
Ad 3. As the Philosopher seems to say in De anima II [422b17-23a21], the sense of touch is one in genus, but is divided into many senses as regards species. For this reason it concerns different contrary pairs. These senses are not separated from one other in terms of organ, but accompany each other throughout the whole body, and as a result it is not obvious that they are distinct. Taste, however, which perceives sweet and bitter, accompanies touch in the tongue, but not throughout the whole body, and so it is easily distinguished from touch. It could be said about all of these contrary pairs, however, that each individual pairing belongs to one proximate genus, and that they all belong to one common genus which is the object of touch, in terms of its common account. But that common genus has no name, just as the proximate genus of hot and cold has no name.°
Ad 4. The sense of taste, according to what the Philosopher says, is a certain species of touch found only in the tongue. It is distinguished from touch not in genus, but in respect of those species [of touch] that are spread throughout the whole body. If, on the other hand, touch is only one sense, in terms of the one common account of its object, then we will have to say that taste is distinguished from touch in terms of the differing character of the impression. For touch is affected not only by a spiritual impression but by a natural one, as regards its organ, in virtue of the quality that is its proper object. The organ of taste, however, is not necessarily affected by a natural impression in virtue of the quality that is its proper object -- so that the tongue becomes sweet or bitter -- but in virtue of the preliminary quality that supports the flavor -- i.e., in virtue of moistness, which is the object of touch.
Article 4. The internal senses
It seems that the internal senses are incorrectly distinguished:°
1. That which is common is not divided against that which is proper. Therefore the common sense should not be counted among the internal sensory powers, as something beyond the external proper senses.
2. No internal apprehensive power needs to be posited for something for which an external proper sense suffices. But the external proper senses suffice for making judgments about sensible things, since each sense makes judgments about its proper object. They likewise seem to suffice for perceiving their own acts. For since the action of a sense is in a certain way in between the capacity and the object, it seems that sight could perceive its own vision much more than it could color, given that the vision is closer to it. And the same is true for the other proper senses. Therefore there was no necessity in positing for this purpose the internal capacity that is called the common sense.
3. According to the Philosopher, the capacities for phantasia and memory are states of the first sensory capacity. But no state is divided against its subject. Therefore memory and phantasia should not be held to be distinct capacities beyond sense.
4. The intellect depends on the senses less than does any capacity of the sensory part. But the intellect cognizes nothing it does not take in from the senses; thus it is said in Posterior Analytics I [81a38] that whoever lacks one of the senses lacks one branch of knowledge. All the less, therefore, should we posit a capacity of the sensory part for perceiving intentions that the senses do not perceive, a capacity they call the estimative.°
5. The act of the cogitative power (adding, composing, and dividing) and the act of the recollective power (making use of syllogisms in inquiry) are no more distant from the act of the estimative and memory powers than the act of the estimative is distant from the act of phantasia. Therefore either the cogitative and recollective powers should be held to differ from the estimative and memory powers, or the estimative and memory powers should not be held to differ from phantasia.
6. Augustine, in De genesi ad litteram XII [vi-vii], posited three kinds of vision: bodily, which occurs through sense, spiritual, which occurs through imagination or phantasia, and intellectual, which occurs through intellect. Therefore no internal power comes between sense and intellect, except for the imaginative power alone.
On the contrary. Avicenna, in his Liber de anima [I.5, IV.1], posits five internal sensory capacities: common sense, phantasia, the imaginative capacity, the estimative capacity, and memory.
Reply. Because nature does not fail in necessary things, there must be as many actions on the part of the sensory soul as are adequate for the life of a complete animal.° And all of those actions that cannot be reduced to a single principle require distinct capacities: for a capacity of the soul is nothing other than the proximate principle of an operation belonging to soul.
One must recognize, however, that the life of a complete animal requires that it apprehend a thing not only when that which is sensible is present, but also when it is absent. Otherwise, since the movement and action of an animal follow apprehension, the animal would not be moved to seek anything absent. The opposite of this is evident above all in complete animals, which move from place to place: for they are moved toward something absent that has been apprehended. Therefore, through the sensory soul an animal must not only receive the species of things that are sensible when they, being present, make an impression on that animal, but it must also retain and preserve these species. But in the case of corporeal things, receiving and retaining are traced to different principles,° since wet things are good at receiving and bad at retaining, whereas the opposite is true for dry things. Consequently, since a sensory capacity is the actuality of a corporeal organ, there must be one capacity that receives the species of things that are sensible, another that preserves them.
One must further recognize that if an animal were moved only by what is pleasant and painful to the senses, it would be necessary to posit in an animal only the apprehension of forms perceived by the senses, in which it would take pleasure or fright. But it is necessary for an animal to seek or flee from things not only because they are or are not agreeable to the senses, but also for the sake of some further benefits and uses, or harms. Thus the sheep flees when it sees the wolf, not because its color or shape is unattractive, but as if because the wolf is harmful to the sheep's nature.° Likewise, a bird collects straw, not because that pleases its senses, but because it is useful for nest building. Therefore it is necessary for an animal to perceive intentions of this sort, which the external senses do not perceive.° And there must be some other principle for this perception, since the perception of sensible forms is the result of an impression from something sensible, whereas the perception of these intentions is not.
So the proper senses and the common sense are directed at receiving sensible forms; the difference between the two will be discussed below [ad 1-2]. Phantasia or imagination (the two are the same) is directed at the retention or preservation of these forms. For phantasia (or imagination) serves as a kind of treasury for forms grasped through the [external] senses. The estimative power is directed at apprehending intentions that are not grasped through the [external] senses. And the power for memory, which is a kind of treasury for intentions of this kind, is directed at their preservation. An indication of this is that the principle for remembering is formed in animals from an intention of this kind -- for instance, that a thing is harmful or agreeable. And the very character of being in the past, with which memory is concerned, is counted among intentions of this kind.
One must recognize, however, that with regard to sensible forms there is no difference between a human being and other animals. For they receive a similar impression from external sensible things. But there is a difference with regard to the intentions under discussion. For other animals perceive these intentions only through a kind of natural instinct, whereas a human being also makes a kind of comparison. And so that which in other animals is called the natural estimative power is called the cogitative power in a human being; it discovers such intentions through comparison. Hence it is also called particular reason (to which physicians have assigned a definite organ, the middle part of the head),° because it compares individual intentions just as intellective reason compares universal intentions. Also, with regard to the power for memory, a human being has not only memory, as do other animals, in the direct recall of past events, but also recollection, which inquires as if syllogistically into memories of past events, in light of individual intentions.
Avicenna, however, posits a fifth capacity in between the estimative and imaginative powers, one that composes and divides imagined forms.° An example is when from the imagined form of gold and the imagined form of a mountain we compose the single form of a gold mountain, something we have never seen. But this operation appears in no animals other than human beings, in whom the imaginative power suffices to do this. And Averroes too attributes this action to that power, in his De sensu [40-41].
Consequently, it is not necessary to posit more than four internal powers of the sensory part:
· common sense
· the estimative power
Ad 1. An internal sense is called common not by way of predication, as a genus is common [to many particulars],° but as the common root and principle of the external senses.
Ad 2. A proper sense makes judgments about its proper sensible, discerning it from others that fall under the same sense -- discerning white from black or green, for example. But neither sight nor taste can discern white from sweet, because that which discerns between two things must cognize both. Consequently, this discerning judgment must pertain to the common sense, to which all sensory apprehensions are conveyed, as to their common terminus. The common sense also perceives sensory intentions, for example when someone sees that he is seeing. For this cannot take place through a proper sense, because it cognizes only the form of the sensible thing that makes an impression on it. In this impression seeing is completed, and as a result of this impression another impression follows in the common sense, which perceives the seeing.
Ad 3. Just as one capacity originates in the soul, mediated by another (as was said above [77.7cxx]), so too the soul is the subject of one capacity, mediated by another. It is in this way that the capacities for phantasia and memory are said to be states of the first sensory capacity.
Ad 4. Although the operation of intellect originates in the senses, nevertheless the intellect cognizes much in a thing apprehended by sense that the sense cannot perceive. The same is true for the estimative power, though in a lesser way.
Ad 5. The cogitative and memory powers have their superiority in a human being not through something proper to the sensory part, but through a kind of affinity and closeness to universal reason, in virtue of some kind of spill over. Consequently they are not different powers, but the same ones, more perfect than in other animals.
Ad 6. Augustine says that spiritual vision is what takes place through the likenesses of bodies, in the absence of those bodies. And so clearly this is common to all inner apprehensions.
Question 79. The Soul's Intellective Capacities
The next question concerns the intellective capacities, and here there are thirteen points of inquiry:
a1. Is the intellect a capacity of the soul, or the soul's essence?
a2. If it is a capacity, is it a passive capacity?
a3. If it is a passive capacity, should we posit an agent intellect?
a4. Is it part of the soul?
a5. Is there one agent intellect for everyone?
a6. Is memory in intellect?
a7. Is it a different capacity from intellect?
a8. Is reason a different capacity from intellect?
a9. Are higher and lower reason distinct capacities?
a10. Is intelligence a different capacity from intellect?
a11. Are speculative and practical intellect distinct capacities?
a12. Is synderesis a capacity of the intellective part?
a13. Is conscience a capacity of the intellective part?
Article 1. Is the intellect a capacity of the soul,
or the soul's essence?
It seems that the intellect is not one of the soul's capacities, but instead the soul's very essence:
1. Intellect seems to be the same as mind. But mind is not a capacity of the soul, but its essence. For Augustine says in De trinitate IX [ii.2] that "`mind' and `spirit' are not relational terms, but pick out the essence." Therefore the intellect is the soul's very essence.
2. Different kinds of capacities of the soul are united not in any one capacity, but only in the soul's essence. But the appetitive and the intellective are different kinds of capacities of the soul, as is said in De anima II [414a31-32]. They are, however, both found in the mind: for in De trinitate X [xi.18], Augustine locates intelligence and will in the mind. Therefore mind (and intellect) is the soul's very essence, not one of its capacities.
3. According to Gregory, in his homily on the ascension, a human being uses intellect "with the angels." But angels are called minds and intellects. Therefore the human mind and intellect is not one of the soul's capacities, but rather the soul itself.
4. A substance is intellective as a result of being immaterial. But the soul is essentially immaterial. Therefore it seems that the soul is essentially intellective.
On the contrary. The Philosopher treats the intellective part as a capacity of the soul, as is clear in De anima II [414a31-32].
Reply. It is necessary to say, in keeping with earlier claims [Q77], that the intellect is one of the soul's capacities and not the soul's very essence. For the essence of the thing operating is the immediate basis of its operation only when that operation is its existence. For just as a capacity is related to its operation as to its actuality, so essence is related to existence. But only in God's case is his intellective operation the same as his existence. Consequently, it is only in God's case that his intellect is his essence; in created intellectual beings, the intellect is a capacity of the creature using it.
Ad 1. `Sense' is sometimes taken for the capacity, sometimes for the sensory soul itself. For the sensory soul is named after its most prominent capacity, which is sense. Likewise, the intellective soul is sometimes given the name `intellect,' inasmuch as this is its most prominent power. (So it is said in De anima I [408b18] that the intellect is a substance.) It is also in this way that Augustine says that the mind is the "spirit" or "essence."
Ad 2. The appetitive and the intellective are different kinds of capacities of the soul in virtue of their objects' different characters. But the appetitive goes in part with the intellective and in part with the sensory, depending on whether it operates through a corporeal organ or without such an organ. For appetite follows apprehension. Accordingly, Augustine locates will in the mind and the Philosopher locates it in reason.
Ad 3. There are no other powers in angels except for the intellective power and will, which follows from intellect. And so an angel is called a mind or an intellect because its entire power consists in this. But the soul has many other powers, such as the sensory and the nutritive, and so the cases are not similar.
Ad 4. The immateriality of a created intellective substance is not its intellect. Rather, it has the power of intellect because of its immateriality. As a result, the intellect need not be the soul's substance; instead, it is the soul's power and capacity.
Article 2. Is the intellect a passive capacity?
It seems that the intellect is not a passive capacity:
1. Everything is acted on with respect to its matter and acts because of its form. But the intellective power is a result of the immateriality of the substance that possesses it. Therefore it seems that the intellect is not a passive power.
2. The intellective capacity is incorruptible, as was said above [75.6]. But the intellect, if it is passive, is corruptible, as is said in De anima III [430a24-25]. Therefore the intellective capacity is not passive.
3. That which acts is loftier than that which is acted on, as Augustine says in De Genesi ad litteram XII [xvi.33] and Aristotle says in De anima III [430a18-19]. But all the capacities of the vegetative part are active, and they are the lowest of the soul's capacities. Therefore, a fortiori, the intellective capacities, the highest of the soul's capacities, are all active.
On the contrary. The Philosopher says in De anima III [429b25] that the operation of intellect consists in being acted on in a certain way.
Reply. There are three ways in which a thing can be said to be acted on. The first way, the strictest, is when a thing has something removed from it that suits it by nature or by its own proper tendency. Examples are when water loses its coldness by being heated, and when a person becomes sick or sad.
In a second, less strict way, someone is said to be acted on as a result of something's being removed from him, regardless of whether that thing suits him. In this way, not only is someone who becomes sick said to be acted on, but also someone who is made well, and not only someone who is made sad, but also someone who is made cheerful. This applies to any way in which something is altered or moved.
In a third, broad way, a thing is said to be acted on simply because that which is in potentiality for something receives what it was in potentiality for, without anything's being taken away. In this way, everything that goes from potentiality to actuality can be said to be acted on, even when it is being completed.
It is in this third way that the operation of our intellect consists in being acted on, as is evident through the following argument:
The operation of intellect, as was stated above [78.1cxx], concerns universal being. Therefore one can determine whether the intellect is in actuality or potentiality by determining how the intellect stands relative to universal being. For there is one intellect that stands to universal being as the actuality of all being ── this is the divine intellect, the essence of God. All being preexists here, originally and virtually, as in its first cause. Consequently, the divine intellect is not in potentiality, but is pure actuality. But no created intellect can stand as actuality relative to all universal being; for, if so, then it would have to be an infinite being. And so every created intellect, by virtue of its very existence, is not the actuality of all intelligible things, but relates to those intelligibles as potentiality to actuality.
But potentiality stands to actuality in two ways. One kind of potentiality is always perfectly actualized; this is how we described the matter of celestial bodies. The other kind of potentiality is not always in actuality, but goes from potentiality to actuality, as do things that undergo generation and corruption. So an angelic intellect is always in actuality with respect to its intelligible objects, on account of its closeness to the first intellect, which is pure actuality (as was said above [cxx]). But the human intellect, which is ranked the lowest of intellects and is the most remote from the divine intellect's perfection, is in potentiality with respect to intelligible things. It is at first like a tablet on which nothing has been written, as the Philosopher says in De anima III [430a1]. This is clearly evident from the fact that we understand only potentially at first, whereas later we are made to understand actually. It is clear, therefore, that our intellect's operation consists in being acted on in a certain way: in the third way of being acted on. Consequently, the intellect is a passive capacity.
Ad 1. That objection holds of being acted on in the first and second ways, which are characteristic of prime matter. But the third way of being acted on belongs to anything existing in potentiality that is brought to actuality.
Ad 2. Some say that the passive intellect is sensory appetite, where the soul's passions are found. In Ethics I [1102b25], as well, sensory appetite is said to be rational by participation, because it "obeys reason." Others say that the passive intellect is the cogitative power, which is called particular reason. Either way, it can be considered passive according to the first two ways of being acted on, inasmuch as this so-called intellect is the actuality of a bodily organ. But the intellect that is in potentiality for intelligible things, which Aristotle for this reason calls the possible intellect,H is passive only in the third way, because it is not the actuality of a corporeal organ. And as a result it is incorruptible.
Ad 3. That which acts is loftier than that which is acted on, if the acting and the being acted on concern the same object. This is not always the case, however, if they concern different objects. Now the intellect is a power that is passive with respect to all universal being, whereas the vegetative is active with respect to one particular being: the body that forms a composite with the soul. As a result, nothing prevents this sort of passive power from being loftier than that kind of active power.
Article 3. Should we posit an agent intellect?
It seems that we should not posit an agent intellectH:
1. Just as the senses are related to sensible things, so our intellect is related to intelligible things. But because the senses are in potentiality for sensible things, we do not posit an agent sense, but only a passive sense. Therefore, since our intellect is in potentiality for intelligible things, it seems that we should not posit an agent intellect, but only a possible intellect.
2. Suppose someone says that there is an agent in the sensory case as well, namely, light.
On the contrary, light is required for sight inasmuch as it makes the medium actually luminous. For color is capable in its own right of moving a luminous medium. But in the case of the intellect's operation, no medium is posited that needs to be actualized. Therefore there is no need to posit an agent intellect.
3. An agent's likeness is received in the thing affected according to the mode of the thing affected. But the possible intellect is an immaterial power. Therefore its immateriality suffices for forms to be received in it immaterially. But a form is actually intelligible as a result of its being immaterial. Therefore there is no need to posit an agent intellect for actualizing intelligible species.
On the contrary. The Philosopher says in De anima III [430a10-15] that, as in every nature, so too in the soul there is something "with which all things are made" and something "with which it makes all things." Therefore we should posit an agent intellect.
Reply. On Plato's view, there is no need to posit an agent intellect for actualizing intelligible things, although perhaps it is needed for supplying an intelligible light to someone using his intellect, as will be said below [79.4]. For Plato claimed that the forms of natural things subsist without matter, and as a consequence he claimed that they are intelligible, since a thing is actually intelligible as a result of being immaterial. Forms of this sort he called Species or Ideas. He said that by participation in these, corporeal matter is formed, so that individuals are established naturally in their proper genera and species. By this, too, our intellects [are formed], so that we have knowledge of the genera and species of things.
But because Aristotle did not claim that the forms of natural things subsist without matter, and because forms existing in matter are not actually intelligible,H it followed that the natures or forms of sensible things (the things that intellect understands) are not actually intelligible. But nothing is brought from potentiality to actuality except through something that is actualH ── as the senses are actualized by something actually sensible. Therefore he needed to postulate a power on the side of intellect to actualize intelligible things by abstracting the species from material conditions. And this is why it is necessary to posit an agent intellect.
Ad 1. Sensible things occur in actuality outside the soul, and so there was no need to posit an agent sense. And in this way it is clear that in the nutritive part all the capacities are active, whereas in the sensory part they are all passive, and in the intellective part there is an active and a passive component.
Ad 2. There are two views on the effect of light. Some say that light is required for sight in order to make colors actually visible. On this view, an agent intellect would be required for thinking in the same way and for the same reason that light is required for seeing. According to others, light is required for seeing not because it makes colors actually visible, but because it makes the medium actually luminous, as the Commentator says in De anima II . On this view, the likeness that Aristotle draws between agent intellect and light is to be considered as follows: Just as the one is necessary for seeing, so the other is necessary for thinking, but not for the same reason.
Ad 3. Supposing there is an agent, then it is indeed the case that the agent's likeness is differently received in different things on account of their different states. But if the agent does not already exist, then the state of the recipient will do nothing in this regard. Now nothing existent in the natural world is actually intelligible (speaking of the nature of sensible things, which do not subsist outside of matter). As a result, the possible intellect's immateriality does not suffice for thought unless there is an agent intellect, which actualizes intelligible things by means of abstraction.
Article 4. Is the agent intellect part of the soul?
It seems that the agent intellect is not part of the soul:
1. The effect of agent intellect is illumination for the sake of understanding. But this is done through something higher than the soul, according to John 1.9: It was the true light that illuminates every human being coming into this world. Therefore it seems that the agent intellect is not part of the soul.
2. The Philosopher says of the agent intellect, in De anima III [430a22], that "it is not sometimes thinking, sometimes not thinking." But our soul is not always thinking: sometimes it thinks and sometimes it does not. Therefore the agent intellect is not part of our soul.
3. The agent and the thing acted on suffice for acting. Therefore if the possible intellect, a passive power, is part of our soul, and likewise for agent intellect, an active power, then it follows that a human being could always understand when he wished, which is clearly false. Therefore the agent intellect is not part of our soul.
4. The Philosopher says in De anima III [430a18] that the agent intellect is "in substance an actual being." But nothing is both in actuality and in potentiality in the same respect. Therefore if the possible intellect, which is in potentiality for all intelligible things, is part of our soul, then it seems impossible for the agent intellect to be part of our soul.
5. If the agent intellect is part of our soul, it must be a capacity. For it is neither a passive alteration (passio) nor a disposition, since dispositions and alterations do not play the role of an agent with respect to our soul's alterations. (Rather, a passive alteration is the action itself of a passive capacity, whereas a disposition is something that follows from acts.) But every capacity flows from the soul's essence. Therefore it would follow that the agent intellect comes from the soul's essence, and so is not in the soul through participation from some higher intellect. That is unacceptable. Therefore the agent intellect is not part of our soul.
On the contrary. The Philosopher says in De anima III [430a13-14] that "it is necessary for there to be these differences in the soul" ── namely, a possible and an agent intellect.
Reply. The agent intellect that the Philosopher describes is part of the soul. To make this clear, keep in mind that it is necessary to posit, above the human intellective soul, a higher intellect from which the soul receives the power to understand. For it is always the case that what  participates in something,  is moveable and  is incomplete, presupposes something prior that is [a] essentially such, [b] unmoveable and [c] complete. But  the human soul is said to be intellective by participating in an intellective power. An indication of this is that it is intellective not as a whole, but in part. Also,  it reaches an understanding of the truth through inference and motion, by framing arguments. Also,  it has an incomplete understanding, both because it does not understand all things, and because with respect to what it does understand, it goes from potentiality to actuality. So there must be some higher intellect by which the soul is helped to understand.
Some, then, have claimed that this intellect, separate in substance, is the agent intellect that by (as it were) illuminating phantasms makes them actually intelligible. But, given that there is some such separate agent intellect, one must still posit in the human soul itself a power taken by participation from that higher intellect, and through which the human soul actualizes intelligible things. In this case as with other complete natural things, in addition to the universal causal agents, distinct powers have been given to complete individuals, powers that have been derived from those universal agents. For it is not the sun alone that generates human beings: humans themselves possess the power to generate human beings, and the same holds true for other complete animals. But, in this lower world, nothing is more complete than the human soul. It must be maintained, then, that the soul has a power derived from a higher intellect, through which it can illuminate phantasms. This is something we recognize through experience, when we perceive ourselves abstracting universal forms from particular conditions, which is to make things actually intelligible. An action belongs to something, however, only on the basis of some principle that inheres in it formally, as was said above when discussing the possible intellect. Therefore the power that is the principle of this action must be something in the soul.
Aristotle, accordingly, compared the agent intellect to light, which is something received in the air, whereas Plato compared the separate intellect influencing our souls to the sun. (Themistius makes this point in his commentary on De anima III.) But according to the teachings of our faith, the separate intellect is God himself, the creator of the soul, in whom alone it achieves happiness, as will be clear below [1a2ae 3.7]. Accordingly, the human soul participates in intellectual light through God, as is said in Psalm 4.7: The light of your face, Lord, is imprinted on us.
Ad 1. That true light illuminates as a universal cause from which the human soul derives through participation one particular power, as was said [cxx].
Ad 2. The Philosopher says those words not about the agent intellect, but about the intellect in actuality. It was of it that he had just remarked, "actualized knowledge is the same as the thing" [430a19-20]. Alternatively, if these words are taken to refer to the agent intellect, then they are said because the fact that we are sometimes thinking and sometimes not thinking is due not to the agent intellect, but to the intellect that is in potentiality.
Ad 3. If the agent intellect were related to the possible intellect as an active object is related to a capacity (e.g., as something actually visible, to sight), then it would follow that we would immediately understand all things, since the agent intellect is "that with which it makes all things." In fact, however, the agent intellect is not the object, but that which actualizes the objects. In addition to the presence of the agent intellect, this requires [a] the presence of phantasms, [b] the good condition of the sensory powers, and [c] practice in activity of this sort ── for one thing grasped by intellect leads to others, as terms lead to propositions and first principles lead to conclusions. And in this connection it makes no difference whether the agent intellect is part of the soul or separated.
Ad 4. The intellective soul is actually immaterial, but is in potentiality for the determinate species of things. Phantasms, in contrast, are the actual likenesses of certain species, but are potentially immaterial. As a result, there is nothing that prevents one and the same soul, inasmuch as it is actually immaterial, from having one power through which it makes things actually immaterial by abstracting from the conditions of individual matter, a power that is called the agent intellect, and another power that receives such species, which is called the possible intellect inasmuch as it is in potentiality for species of this sort.
Ad 5. Since the soul's essence is immaterial and was created by the supreme intellect, there is nothing to prevent the power it participates in through that supreme intellect (the power by means of which it abstracts from matter) from coming from the soul's essence, just as the soul's other capacities do.
Article 5. Is there one agent intellect for everyone?
It seems that the agent intellect is one in everyone:
1. Nothing separate from body is multiplied by multiplying bodies. But the agent intellect is separate, as is said in De anima III [430a22]. Therefore it is not multiplied in the multiple bodies of human beings, but is one in everyone.
2. The agent intellect makes the universal, which is one in many. But that which is the cause of oneness must itself, even more, be one thing. Therefore there is one agent intellect in everyone.
3. All human beings share their first intellectual conceptions. But they assent to these through agent intellect. Therefore they all share one agent intellect.
On the contrary. The Philosopher says in De anima III [430a15-17] that the agent intellect is like light. But different subjects of illumination do not have the same light. Therefore different human beings do not have the same agent intellect.
Reply. The truth of this question rests on earlier claims [79.4]. For if the agent intellect were not part of the soul, but were some kind of separate substance, then there would be one agent intellect for all human beings. And this is what those who posit the unity of agent intellect have in mind. If, however, the agent intellect is part of the soul, as a kind of power belonging to it, then it is necessary to say that there are many agent intellects, inasmuch as there are many souls, which are multiplied according to the number of human beings, as was said above [76.2]. For it cannot be that numerically one and the same power belongs to different substances.
Ad 1. The Philosopher proves that the agent intellect is separate through the fact that the possible intellect is separate. For, as he says, "the agent is worthier than the patient." But the possible intellect is said to be separate because it is not the act of any corporeal organ. And in this way the agent intellect too is said to be separate ── not as if it is a separate substance.
Ad 2. The agent intellect causes the universal by abstracting from matter. But this does not require that it be one in all things having an intellect. Instead, it must be one with regard to its relationship to all the things from which it abstracts the universal, relative to which the universal is one. And this holds of the agent intellect insofar as it is immaterial.
Ad 3. All members of a single species share in [any] action that is due to the nature of that species. As a result, they share in the power that is the principle of that action, although not in such a way that it is numerically the same power in all. But to cognize the first objects of intellect is an action that is due to the human species. So all human beings must share in the power that is the principle of this action: this is the power of agent intellect. It does not have to be numerically the same in everyone, but it does, in everyone, have to be derived from one principle. Thus the fact that human beings share in the first objects of intellect demonstrates the unity of the separate intellect (which Plato compares to the sun), but not the unity of the agent intellect (which Aristotle compares to light).
Article 6. Is memory in intellect?
It seems that memory is not in the intellective part of the soul:
1. Augustine says in De trinitate XII [ii.2] that things pertain to the higher part of the soul that "are not shared by human beings and beasts." But memory is shared by human beings and beasts. For he says in the same place that "beasts can sense bodily things through the body's senses, and can commit those things to memory." Therefore memory does not pertain to the intellective part of the soul.
2. Memory concerns things past. But the past is spoken of with reference to some determinate time. Therefore memory cognizes a thing under the aspect of a determinate time, which is to cognize something under the aspect of the here and now. But this is the role of sense, not of intellect. Therefore memory is not in the intellective part, but only in the sensory part.
3. Memory preserves the species of things that are not actually being considered. But this cannot possibly happen in intellect, because the intellect is actualized through being informed by an intelligible species, and the intellect's actuality is its actually thinking. Thus the intellect is actually thinking about all the things whose species it has within it. Therefore memory is not in the intellective part.
On the contrary. Augustine says in De trinitate X [xi.18] that "memory, intelligence, and will are one mind."
Reply. It is the nature of memory to preserve the species of things that are not actually being apprehended. So we must first consider whether intelligible species can be preserved in this way in intellect. Avicenna claimed that this was impossible. For he said that this occurs in the sensory part, with respect to certain capacities, inasmuch as they are the actualities of corporeal organs that can preserve some species without any actual apprehension. But in intellect, which lacks a corporeal organ, nothing exists unless intelligibly, and so that whose likeness exists in intellect must be actually thought about. So in this way, according to Avicenna, as soon as someone actually ceases to think about a thing, the species of that thing ceases to be in intellect. If someone wants to think about that thing another time, he must turn toward the agent intellect (which he posited to be a separate substance), so that intelligible species flow from that intellect to the possible intellect. According to him, training and practice in turning toward the agent intellect leaves one with a certain aptitude in the possible intellect for turning toward the agent intellect, and he claimed that this aptitude is dispositional knowledge. So on this view, nothing is preserved in the intellective part that is not being actually thought. Hence memory could not be located in the intellective part, when considered in this way.
But this view is clearly incompatible with what Aristotle says. For in De anima III [429b5-9] he says that "when the possible intellect becomes the singulars in such a way as to be knowing, it is said to be actualized," and he says that "this happens when it can operate on its own. So even then it is in potentiality in a certain way, but not as it was even before learning or discovering." But the possible intellect is said to become the singulars inasmuch as it receives the species of singulars. Therefore, because it receives the species of intelligible things, it has the ability to operate whenever one wants, but it is not the case that it is always operating. For even then it is in potentiality in a certain way ── not as it was before being engaged in thought, but in the way in which someone with dispositional knowledge is in potentiality for actually considering [a thing].
The position described above is also incompatible with reason. For that which is received in a thing is received according to the mode of the recipient. But the intellect is more stable and unmoving in its nature than is corporeal matter. Therefore if corporeal matter holds onto the forms that it receives not only while it is actually acting through them, but also after it has ceased acting through them, then the intellect receives intelligible species all the more unmoveably and enduringly ── regardless of whether they are received from sensible things or from the influence of some higher intellect. So consequently, if memory is taken only as the power of preserving species, then one must say that memory is in the intellective part. On the other hand, if the nature of memory is that its object be past, as past, then memory will not be in the intellective part, but only in the sensory part, the part that apprehends particulars. For the past, as past, since it signifies existence under the aspect of a determinate time, pertains to a condition of the particular.
Ad 1. Memory, considered as preserving species, is not [entirely] shared by us and by beasts. For species are preserved not in the sensory part of the soul alone, but rather in the compound, since the power of memory is the actuality of a particular organ. But the intellect is in its own right capable of preserving species, without an accompanying corporeal organ. And so the Philosopher says in De anima III [429a27-28] that "the soul is the locus of species ── not the whole soul, but the intellect."
Ad 2. Being past can refer to two things: to the object that is cognized and to the act of cognition. These two are joined together at once in the sensory part, which apprehends a thing through receiving an impression from something sensible that presently exists. As a result, an animal remembers having sensed in the past at the same time that it remembers having sensed some past sensible thing. But with respect to the intellective part, being past applies accidentally to an object of intellect and does not hold per se. For the intellect thinks about a human being qua human being, whereas it is accidental to a human being, qua human being, to be in either the present, the past, or the future.
Yet even in the intellect's case, being past can be taken per se with regard to its act, just as in the case of the senses. For our soul's thinking is a particular act existing at one time or another, depending on whether someone is said to be thinking now, yesterday, or tomorrow. This is not incompatible with its being intellectual, because although such thinking is something particular, it is nevertheless actually immaterial, as was said above about intellect [76.1cxx]. So just as the intellect thinks about itself, even though it itself is a particular intellect, so it thinks about its own thinking, which is a particular act existing in either the past, the present, or the future. So in this way the nature of memory, inasmuch as it concerns things past, is preserved in intellect inasmuch as it thinks that it has previously thought. But it is not preserved with respect to thinking about the past considered as here and now.
Ad 3. An intelligible species is sometimes only potentially in the intellect, and then the intellect is said to be in potentiality. Sometimes it is there inasmuch as the act is entirely complete, and then the intellect is actually thinking. Sometimes it stands midway between potentiality and actuality, and then the intellect is said to have a disposition.H It is in this way that the intellect preserves species, even when it is not actually thinking.
Is intellective memory a different capacity from intellect?
It seems that intellective memory is one capacity, intellect another:
1. Augustine, in De trinitate X [xi.17], locates memory, intelligence, and will in the mind. But it is clear that memory is a different capacity from will. Therefore it is likewise different from intellect.
2. The basis for distinguishing the sensory part's capacities is the same as that for distinguishing the intellective part's capacities. But memory in the sensory part is a different capacity from sense, as was said above [78.4cxx]. Therefore the intellective part's memory is a different capacity from intellect.
3. According to Augustine, memory, intelligence, and will are the equals of each other, and one originates in another. But this could not be, if memory were the same capacity as intellect. Therefore it is not the same capacity.
On the contrary, it is the nature of memory to be the treasury or locus for preserving species. But in De anima III [429a27-28] the Philosopher attributes this to intellect, as was said [79.6 ad 1]. Therefore memory and intellect are not different capacities in the intellective part.
Reply. As was said above [77.3cxx], the soul's capacities are distinguished by the differing natures (rationes) of their objects: for the nature of any capacity consists in its relationship to that toward which it is ordered, which is its object. It was also said above [59.4c] that if a capacity in respect of its own nature is related to an object in respect of the common nature of that object, then that capacity will not be made to differ by differences between particular differentiae. The visual capacity, for example, which relates to its object in respect of the nature of being colored, is not made to differ by the difference between white and black. The intellect, however, relates to its object in respect of the common nature of being: for the possible intellect is "that with which all things are made." Consequently, the possible intellect is not differentiated by any differentia among beings.
But the capacities of agent intellect and possible intellect are differentiated. For with respect to the same object, there must be one principle that is the active capacity, which makes the object actually exist, and another that is the passive capacity, which is moved by the actually existing object. So the active capacity is related to its object as actual being to potential being, whereas conversely the passive capacity is related to its object as potential being to actual being.
Accordingly, then, there can be no other difference of capacities in intellect, other than that between possible and agent. And so it is clear that memory is not a different capacity from intellect. For it belongs to the nature of a passive capacity to preserve, as well as to receive.
Ad 1. Although it is said in Sentences I, distinction 3, that memory, intelligence, and will are three "powers," this nevertheless does not accord with Augustine's view. He expressly says in De trinitate XIV [vii.10] that if memory, intelligence, and will are taken as always being present in the soul, then "whether or not they are being thought about, they seem to pertain only to memory. But I am now speaking of the intelligence by which we understand when thinking, and of the will that is the love or delight joining child and parent together." From this it is clear that Augustine does not take these three for three capacities, but takes memory for the soul's dispositional retention, intelligence for the act of intellect, and will for the act of will.
Ad 2. Past and present can be the proper differentiae distinguishing the sensory capacities, but they do not distinguish the intellective capacities, for the reason given above [cxx; 79.6 ad 2].
Ad 3. Intelligence originates in memory as an act does in a disposition. And in this way, too, they are equals, but not as one capacity to another.
Article 8. Is reason a different capacity from intellect?
It seems that reason is a different capacity from intellect:
1. It is said in the book De spiritu et anima  that "when we want to ascend from lower to higher things, we are presented first with sense, then imagination, then reason, then intellect." Therefore reason is a different capacity from intellect, just as imagination is different from reason.
2. Boethius says in The Consolation of Philosophy [IV prose 6] that intellect is related to reason as eternity to time. But existing in eternity and existing in time do not belong to the same power. Therefore reason and intellect are not the same capacity.
3. A human being has intellect in common with angels, and the senses in common with brute animals. But reason, which is the special attribute of a human being in virtue of which he is called a rational animal, is a different capacity from sense. Therefore, by similar reasoning, it is a different capacity from intellect, which is attributed specially to angels and is why they are called intellectual.
On the contrary. Augustine says in De Genesi ad litteram III [xx.30] that "that by which a human being surpasses nonrational animals is reason, mind, intelligence, or whatever other term there is that more aptly picks it out." Therefore reason, intellect, and mind are one capacity.
Reply. Reason and intellect cannot be distinct capacities in a human being. This is clearly recognized, if the act of each one is considered. For intellection (intelligere) is the apprehending of intelligible truth directly, whereas to reason is to advance from one intellectual object to another so as to cognize the intelligible truth. And thus the angels, because they completely possess the cognition of intelligible truth (in keeping with the state of their nature), have no need to advance from one object to another; they directly and without inference apprehend the truth about things (as Dionysius says in Divine Names 7.2). Human beings, on the other hand, attain the cognition of intelligible truth by advancing from one object to another (as is said in the same passage), and so they are called rational.H
It is clear, then, that reasoning is related to intellection as moving is related to resting, or acquiring to having ── one of these is complete, the other incomplete. And because motion always advances from something immoveable and stops at some resting point, so it is that human reasoning, in the course of investigation and discovery, advances from certain things that are grasped directly by intellect; these are first principles. Then, in the course of judgment, it returns by analysis to those first principles, and relative to these it examines its discoveries.
It is clear, however, that resting and moving are not traced back to distinct capacities, but to one and the same, even in the case of natural things. For it is through the same nature that a thing is moved to a place and rests in that place. A fortiori, then, it is through the same capacity that we engage in intellection and reasoning. And so it is clear that in a human being reason and intellect are the same capacity.
Ad 1. That list corresponds to the order of acts, not to the difference in capacities. Anyway, that book has no great authority.
Ad 2. The reply is clear from what was said. For eternity is related to time as the immoveable to the moveable. That is why Boethius related intellect to eternity and reason to time.
Ad 3. Other animals are so beneath human beings that they cannot reach any cognition of the truth, which is what reason investigates. A human being, in contrast, does reach a cognition of the intelligible truth that angels cognize, but incompletely. And thus the cognitive power of angels is not of a different genus from the cognitive power of reason, but is related to it as the complete to the incomplete.
Article 9. Are higher and lower reason distinct capacities?
It seems that higher and lower reason are distinct capacities:
1. Augustine says in De trinitate XII [vii.12] that an image of the Trinity is in the higher part of reason, not in the lower. But the soul's parts are its capacities. Therefore higher and lower reason are two capacities.
2. Nothing originates in itself. But lower reason originates in higher, and is regulated and directed by it. Therefore higher reason is a different capacity from lower reason.
3. The Philosopher says in Ethics VI [1139a5-15] that the soul's capacity for knowledge, by which the soul cognizes necessary things, is a different principle and a different part of the soul from the capacity for forming opinions and for [practical] reasoning, by which it cognizes contingent things. He proves this through the fact that "sections of the soul are different in genus if they are directed to things different in genus." The contingent and the necessary, however, are different in genus, just as the corruptible and the incorruptible are. Now since the necessary is the same as the eternal, and the temporal the same as the contingent, it seems that what the Philosopher calls the capacity for knowledge is the same as the higher part of reason, which, according to Augustine, is aimed at "contemplating and consulting the eternal." It also seems that what the Philosopher calls the capacity for [practical] reasoning or forming opinions is the same as lower reason, which, according to Augustine [ibid.], is aimed at managing temporal affairs. Therefore higher and lower reason are different capacities of the soul.
4. Damascene says that "opinion comes from imagination; then mind, judging whether the opinion is true or false, judges the truth (and hence the mind is named after measuring); therefore, regarding things that it has already made a judgment and true determination about, it is called intellect." So therefore the capacity for forming opinions, which is lower reason, is different from mind and intellect, which can be understand as higher reason.
On the contrary. Augustine says in De trinitate XII [iv.4] that higher and lower reason are not distinguished, "except through their functions." Therefore they are not two capacities.
Reply. Higher and lower reason, as they are taken by Augustine, cannot in any way be two capacities. For he says that higher reason is what aims at "contemplating and consulting the eternal": contemplating, inasmuch as it considers eternal things in themselves; consulting, inasmuch as it draws rules of action from them. Lower reason, in contrast, is what he says is aimed at temporal things. These two ── temporal and eternal things ── relate to our cognition in this way: that one of them is a means of cognizing the other. For in the course of discovery, we achieve a cognition of eternal things through temporal things ── as the Apostle writes in Romans 1.20: the invisible things of God are clearly seen, understood through the things that have been made. In the course of judgment, in contrast, we make judgments about the temporal through what we have already cognized of the eternal, and we manage the temporal in accord with our conceptions of the eternal.
Now it can happen that the means, and that which is reached through the means, pertain to different dispositions. For example, indemonstrable first principles pertain to a disposition of understanding, whereas conclusions derived from these pertain to a disposition of knowledge. Also, from the principles of geometry someone can reach conclusions in another area of knowledge, such as the science of perspective. But both the means and the ultimate conclusion pertain to the same capacity, reason. For the act of reason serves as a kind of movement reaching from one thing to another, and it is the same moveable thing that crosses through the medium and reaches the endpoint. And so higher and lower reason are one and the same capacity of reason. But they are distinguished, according to Augustine, by the functions of their acts and by their different dispositions. For wisdom is attributed to higher reason, knowledge to lower reason.
Ad 1. One can speak of parts according to any method (rationem) of partition. Higher and lower reason, then, are said to be partitioned insofar as reason is divided into different functions, and not because they are different capacities.
Ad 2. Lower reason is said to be derived from higher reason, or to be regulated by it, inasmuch as the principles that lower reason uses are derived and guided by the principles of higher reason.
Ad 3. The capacity for knowledge that the Philosopher refers to is not the same as higher reason, since necessary objects of knowledge are found even in the temporal, which is what natural and mathematical knowledge concerns. But the capacity for forming opinions and for [practical] reasoning extends to less than does lower reason, because it concerns only contingent things.
Furthermore, we should not maintain absolutely that there is one capacity by which the intellect cognizes necessary things and another by which it cognizes contingent things. For it cognizes both with respect to the same aspect of the object: being and true. And so the intellect has a complete cognition of necessary things, which have complete existence in truth, because it reaches their quiddity, through which it picks out their proper accidents. On the other hand, it has an incomplete cognition of contingent things, just as they have incomplete existence and truth. But being complete and incomplete in actuality do not make the capacity differ, but make the act differ, as regards the manner of acting, and consequently make the principles of the acts differ, as well as the dispositions themselves.
So the Philosopher posited two sections of the soul, the capacity for knowledge and the [practical] reasoning capacity, not because they are two capacities, but because they are differentiated by their different aptitudes for receiving different dispositions. It is this difference that he means to investigate there. For contingent and necessary things, even if they differ in their proper genera, still agree in the common nature of being, which is what the intellect is concerned with. They relate to this being in different ways, as complete and incomplete.
Ad 4. Damascene's distinction holds in terms of a difference in acts, not a difference in capacities. For opinion signifies an act of intellect that arrives at one of two contradictory views with misgivings about the other. Judging or measuring is an act of intellect that applies principles that are certain to an examination of the things proposed. (The term `mind' comes from this.) Intellection, finally, consists in adhering with a kind of approval to things already judged.
Is intelligence a different capacity from intellect?
It seems that intelligence is a different capacity from intellect:
1. It is said in the De spiritu et anima  that "when we want to climb from lower to higher things, we are presented first with sense, then imagination, then reason, then intellect, and finally intelligence." But imagination and sense are distinct capacities. Therefore so are intellect and intelligence.
2. Boethius says in The Consolation of Philosophy V [prose 4] that "a human being is viewed by sense in one way, imagination in another, reason in a third, and intelligence in still one more." But intellect is the same capacity as reason. Therefore it seems that intelligence is a different capacity from intellect, just as reason is a different capacity from imagination and sense.
3. Acts are prior to capacities, as is said in De anima II [415a18-19]. But intelligence is an act that is separate from the other acts attributed to the intellect. For Damascene says that "the first motion [of intellect] is called intelligence; intelligence concerning something is labeled intention; that which endures and shapes the soul to what is understood is called contemplation; contemplation that dwells on the same thing, and examines and judges itself, is called phronesis (i.e., wisdom); phronesis when expanded produces thought, i.e., the speech ordered internally, from which they say comes the speech put forth by the tongue." Therefore it seems that intelligence is a specific kind of capacity.
On the contrary. The Philosopher says in De anima III [430a26-27] that "intelligence concerns indivisible things, in which there is nothing false." But this sort of cognition pertains to intellect. Therefore intelligence is not a different capacity from intellect.
Reply. The term `intelligence,' strictly speaking, signifies the act itself of intellect, understanding. But in various books translated from Arabic, the separate substances that we call angels are called intelligences ── perhaps because substances of this sort are always actually understanding ── whereas in books translated from Greek they are called intellects or minds. It follows, then, that intelligence is distinguished from intellect not as one capacity from another, but as an act from a capacity. For the philosophers do also identify this sort of division. For they sometimes posit four intellects: agent intellect, possible intellect, dispositional intellect, and achieved intellect. Of these four, agent and possible intellect are distinct capacities, just as in all cases an active capacity is different from a passive one. The other three are distinguished in terms of being three states of possible intellect. Sometimes it is merely in potentiality, and so it is called the possible intellect; sometimes it is in first actuality (knowledge), and then it is called dispositional intellect; sometimes it is in second actuality (considering), and then it is called actualized intellect or achieved intellect.
Ad 1. If that authority is to be acknowledged, then intelligence is being treated as an act of intellect. In this way it is divided against intellect, just as act is divided against capacity.
Ad 2. Boethius takes intelligence for an act of intellect that transcends the act of reason. Thus he says in the same place [prose 5] that "reason belongs only to the human kind, just as intelligence belongs solely to the divine." For it is distinctive of God that without any investigation he understands all things.
Ad 3. All those acts that Damascene lists belong to one intellective capacity. This capacity first apprehends something directly, and this act is what he is calling intelligence. Second, it relates what it apprehends to cognizing or doing something else, and this is what he labels intention. When it persists in exploring what it intends, this is labeled contemplation. And when it examines what it had contemplated in light of things that are certain, this is called knowing or being wise, which belongs to phronesis or wisdom. (For judging belongs to wisdom, as is said in Metaphysics I [982a18].) Then, as a result of holding something for certain, as already examined, it thinks about how it could make that clear to others. This is the ordering of internal speech, from which comes external speech.
For not every difference in acts produces a difference in capacities, but only those that cannot be reduced to a single principle, as was said above [78.4cxx].
Article 11. Are speculative and practical intellect
It seems that speculative and practical intellect are distinct capacities:
1. The capacities for apprehending and for moving are distinct kinds of capacities, as is clear in De anima II [414a31-32]. But speculative intellect is for apprehending only, whereas practical intellect is for moving. Therefore they are distinct capacities.
2. The distinct character (ratio) of the object distinguishes the capacity. But the object of speculative intellect is what is true, whereas the object of practical intellect is what is good, and these differ in character. Therefore speculative and practical intellect are distinct capacities.
3. In the intellective part, practical intellect is related to speculative just as the estimative power is related to the imaginative in the sensory part. But the estimative differs from the imaginative as one capacity from another, as was said above [78.4cxx]. Therefore so does practical intellect differ from speculative.
On the contrary. It is said in De anima III [433a14-15] that speculative intellect is made practical by its extension. But one capacity is not changed into another. Therefore speculative and practical intellect are not distinct capacities.
Reply. Practical and speculative intellect are not distinct capacities. The reason for this is that (as was said above [77.3cxx]) something does not make a capacity differ when it is accidentally related to that feature of an object that the capacity is concerned with. For it holds accidentally of something colored that it is a human being, or is large or small, and so all things of this sort are apprehended by the same visual capacity. Now it holds accidentally of something apprehended by intellect that it is or is not related to a task; it is in this connection that speculative and practical intellect differ. For speculative intellect apprehends something without relating it to a task, but only to a consideration of its truth. Practical intellect, in contrast, is said to be what relates to a task the thing it apprehends. This is what the Philosopher says in De anima III [433a15], that speculative intellect differs from practical "in terms of its end." And so each is denoted by its end: the one speculative and the other practical ── i.e., task oriented.
Ad 1. Practical intellect is for moving not in that it carries out the movement, but in that it directs the movement, which it can do because of the way in which it apprehends things.
Ad 2. What is true and what is good include one another. For what is true is something good, otherwise it would not be worthy of appetite (appetibile), and what is good is something true, otherwise it would not be intelligible. Therefore, just as an object of appetite can be true insofar as it has the character of a good (for example, when someone has an appetite to cognize the truth), so an object of practical intellect is a good that can be related to a task under its aspect as something true. For practical intellect cognizes the truth, just as speculative intellect does, but it relates that cognized truth to a task.
Ad 3. There are many differentiae distinguishing the sensory capacities that do not distinguish the intellective capacities, as was said above [77.3 ad 4].
Is synderesis a capacity of the intellective part?
It seems that synderesis is a specific capacity distinct from others:
1. Things that fall under a single division seem to belong to a single genus. But in Jerome's gloss on Ezekiel 1, synderesis is divided from the irascible, concupiscible and rational, which are capacities. Therefore synderesis is a capacity.
2. Opposites belong to a single genus. But synderesis and sensuality seem to be opposed, since synderesis always inclines toward what is good, whereas sensuality always inclines toward what is bad. (That is why it is signified by the serpent, as Augustine makes clear in De trinitate XII [xii-xiii].) Therefore it seems that synderesis is a capacity just as sensuality is.
3. Augustine says in De libero arbitrio [II.x.29] that in our natural power for judgment there are certain "rules and seeds of the virtues, both true and unchangeable." But this is what we call synderesis. Therefore, since the unchangeable rules by which we judge belong to reason in its higher part, as Augustine says in De trinitate XII [ii.2], it seems that synderesis is the same as reason. And so it is a capacity.
On the contrary. Rational capacities are open to opposites, according to the Philosopher. Synderesis, however, is not open to opposites, but inclines one only to what is good. Therefore synderesis is not a capacity. For if it were a capacity then it would have to be a rational capacity, since it is not found in brute animals.
Reply. Synderesis is not a capacity, but a disposition ── even though some have claimed that synderesis is a capacity higher than reason, and others have said that it is reason itself, not qua reason but qua nature. To make this clear we must take into account, as was said above [79.8cxx], that human reasoning, since it is a kind of motion, sets off from an understanding of some things (those naturally known without rational investigation), as from a certain immoveable principle, and also ends up at an understanding insofar as, through principles naturally known per se, we make judgments about things that we discover by reasoning. It is plain, however, that just as speculative reason reasons about speculative matters, so practical reason reasons about possible actions (operabilibus). Therefore, just as principles about speculative matters are naturally imparted to us, so are principles about possible actions. But the first principles about speculative matters naturally imparted to us do not belong to any specific capacity, but to a specific disposition which is called the understanding of principles (as is clear in Ethics VI [1140b31-41a8]). Accordingly, principles concerning possible actions that are naturally imparted to us belong not to a specific capacity, but to a specific natural disposition, which we call synderesis. Thus synderesis is said to incite us toward what is good, and to scold us about what is bad, inasmuch as through first principles we move on to discover things and we make judgments about those discoveries. Therefore it is clear that synderesis is not a capacity, but a natural disposition.
Ad 1. Jerome's division is concerned with the distinction among acts, not the distinction among capacities. But a single capacity can have distinct acts.
Ad 2. The opposition between sensuality and synderesis is likewise concerned with the opposition between acts ── not between distinct species of a single genus.
Ad 3. Unchangeable reasons of this sort are the first principles of possible actions; with respect to these it is not possible to err. They are attributed to reason as their capacity, and to synderesis as their disposition. That is why we naturally make judgments through both reason and synderesis.
Is conscience a capacity of the intellective part?
It seems that conscienceH is a capacity:
1. Origen says that conscience is "the correcting and guiding spirit associated with the soul, by which it is separated from bad things and adheres to good things." But `spirit in the soul' refers either to some capacity, or to the mind itself (as in Ephesians 4.23: Be renewed in the spirit of your mind), or to the imagination (and so an imaginary vision is called spiritual, as is clear in Augustine, De Genesi ad litteram XII [xii.25-26]). Therefore conscience is a capacity.
2. Nothing is subject to sin except a capacity of the soul. But conscience is subject to sin. For it is said of some in Titus 1.15 that their mind and conscience are defiled. Therefore it seems that conscience is a capacity.
3. It is necessary for conscience to be either an act, a disposition, or a capacity. But it is not an act, since then it would not always remain in a human being. Nor is it a disposition, since then conscience would not be some one thing, but many. For we are guided in our actions through many cognitive dispositions. Therefore conscience is a capacity.
On the contrary, conscience can be set aside, whereas a capacity cannot. Therefore conscience is not a capacity.
Reply. Conscience, properly speaking, is not a capacity but an act. This is clear both  on the basis of its name and  from the things we attribute to conscience in our common ways of speaking.
 For conscience, in terms of the word's own proper character, implies the relationship of knowledge to something: for `conscience' means knowledge with another (cum alio scientia). But the application of knowledge to something takes place through some act. So it is clear from the very nature of its name that conscience is an act.
 The same is evident from the things that are attributed to conscience. For conscience is said to bear witness, to bind, to incite, and also to accuse, to torment, or to rebuke. And all of these follow the application of some of our cognition or knowledge to the things that we do. This application occurs in three ways:
C First, inasmuch as we recognize that we have or have not done something. As Ecclesiastes 7.23 says: your conscience knows that you have often spoken evil of others. In this regard, conscience is said to bear witness.
C It is applied in another way inasmuch as we judge through our knowledge that something should or should not be done. In this regard, conscience is said to incite or to bind.
C It is applied in a third way inasmuch as we judge through knowledge that something that was done was or was not done well. And in this way conscience is said either to excuse or to accuse or torment.
It is clear, however, that all of these result from an actual application of knowledge to the things that we do. Properly speaking, then, `conscience' refers to an act.
But because a disposition is the basis for an act, the term `conscience' is sometimes attributed to the first natural disposition, synderesis. Thus Jerome, in his gloss on Ezekiel 1, refers to synderesis as "conscience," Basil refers to conscience as "the natural power for judgment," and Damascene says that it is "the law of our intellect." For it is not unusual to refer to causes and effects through each other.
Ad 1. Conscience is said to be a spirit insofar as `spirit' is used for mind. For it is a kind of dictate of the mind.
Ad 2. Defilement is said to be in conscience not as its subject, but as something cognized is in the cognition ── inasmuch, that is, as someone knows himself to be defiled.
Ad 3. An act, even if it does not always remain in its own right, still always remains in its cause, which is the capacity and its dispositions. But the dispositions that inform conscience, even if there are many of them, all draw their efficacy from one first disposition ── namely, from the disposition for first principles that is called synderesis. Hence this disposition especially is sometimes referred to as conscience, as was said above [cxx].
Question 84. What does the soul cognize bodies through?
Next we must consider the soul's acts, with respect to the intellective and appetitive capacities. For the soul's other capacities do not directly concern the investigations of the theologian. But the acts of the appetitive part are the concern of an investigation into the science of morality, and so we will take up these matters in the second part of this work, where we will need to investigate moral questions. For now, we will deal with the acts of the intellective part.
In investigating its acts, we will proceed in this way: First, we must consider how the soul understands when connected to its body; second, how it does so when separated from its body [Q89]. The first investigation will have three parts: First we will investigate how the soul understands the bodily things below it; second, how it understands itself and the things within it [Q87]; third, how it understands the immaterial substances above it [Q88].
As regards the cognition of bodily things, there are three subjects of investigation: First, what it cognizes these things through; second, how and in what order [Q85]; third, what it cognizes in them [Q86].
As regards the first, there are eight points of inquiry:
a1. Does the soul cognize bodies through intellect?
a2. Does it understand them through its essence or through species?
a3. If through species, are the species of all intelligible things naturally innate in it?
a4. Do they emanate from certain separate immaterial forms, into the soul?
a5. Does our soul see all the things that it understands in their eternal natures?
a6. Does it acquire intelligible cognition from sensation?
a7. Does it need phantasms in order actually to understand?
a8. Is the intellect's judgment impeded by an impediment to the sensory powers?
Article 1. Does the soul cognize bodies through intellect?
It seems that the soul does not cognize bodies through intellect:
1. Augustine says in Soliloquies II [iv.6] that "bodies cannot be grasped by intellect ... nor can anything bodily be seen, except by the senses." He also says, in De Genesi ad litteram XII [xxiv.50], that intellectual vision is of those things that are in the soul in their own right (per essentiam suam). But bodies are not like that. Therefore the soul cannot cognize bodies through intellect.
2. Just as sense is related to intelligible things, so intellect is related to sensible things. But the soul can in no way cognize spiritual things, which are intelligible, through sense. Therefore it can in no way cognize bodies, which are sensible, through intellect.
3. The intellect concerns things that are necessary and always disposed in the same way. But all bodies are changeable° and not disposed in the same way. Therefore the soul cannot cognize bodies through intellect.
On the contrary. Science is in intellect.° Therefore, if the intellect were not to cognize bodies, it would follow that there is no science of bodies. And so natural science, which concerns changeable bodies, will cease to exist.
Reply. To clarify this question it should be said that the first philosophers, who investigated the natures of things, believed that there is nothing in the world except for bodies. And because they saw that all bodies are changeable, and they believed them to be in constant flux, they judged that we could have no certainty about the truth of things.° For that which is in constant flux cannot be apprehended with certainty, since it slips away before it can be assessed by the mind. Thus Heraclitus said that it is not possible to touch the water in a flowing river twice (as the Philosopher reports in Metaphysics IV [1010a14]).
After these philosophers came Plato. In order to be able to ensure that our intellect had certain cognition of the truth, he posited, beyond the bodily, entities of another sort, separate from matter and motion. He named these Species or Ideas. Through participation in them, each and every singular and sensible thing is said to be either a human being, a horse, or some other such thing.° In this way, then, he said that the sciences, definitions, and whatever pertains to the act of intellect refer not to bodily sensible things, but to those immaterial and separate Ideas, so that as a result the soul understands not those bodily things, but the separate Species of bodily things.
It is apparent in two ways that this is false. First, since those Species are immaterial and unchangeable, we would have to exclude from the sciences [a] the cognition of motion and matter (which is what distinguishes natural science) and [b] demonstration through moving and material causes. Second, it seems ridiculous that, in seeking knowledge of things that are evident to us, we should introduce other intervening entities that cannot be their substances, since they differ from them in being.° The result would be that even if we were to cognize those separate substances, we could not on that basis make any judgment about sensible things.
It seems that Plato strayed from the truth in this way: since he took all cognition to occur by means of some likeness, he believed that the form of the thing cognized must necessarily be in the one cognizing in the way it is in the thing cognized. But he recognized that the form of the thing understood is in intellect universally, immaterially, and unchangeably, a fact that is apparent from the operation of intellect, which understands universally, in a certain necessary mode. For an agent's mode of action accords with the mode of its form. As a result, Plato held that the things understood must have this mode of subsisting in their own right ── that is, immaterially and unchangeably.
But this is not necessary. For even in sensible things themselves we see that a form is in one sensible differently than it is in another. For instance, in one thing whiteness is more intense, in another it is less intense; in one thing whiteness comes with sweetness, in another without sweetness. And in this way, too, a sensible form is in the thing outside the soul differently than it is in a sense, which receives the forms of sensible things without their matter (like the color of gold, without the gold°). In the intellect, likewise, the species of bodies, which are material and changeable, are received immaterially and unchangeably, according to the intellect's own mode. For that which is received is in the recipient according to the mode of the recipient. Therefore it must be said that the soul, through intellect, cognizes bodies by means of a cognition that is immaterial, universal, and necessary.
Ad 1. Augustine's claim should be understood with respect to the things by which the intellect cognizes, not with respect to the things that it cognizes. For in understanding it does cognize bodies, but not through bodies, nor through material and bodily likenesses, but through species that are immaterial and intelligible, which can be in the soul in their own right.
Ad 2. As Augustine says in City of God XXII , it should not be said that, just as the senses cognize only bodily things, so the intellect cognizes only spiritual things ── for then it would follow that God and the angels would not cognize bodily things. The reason there is this difference is that a lower power does not extend itself to the things belonging to a higher power. But a higher power carries out in a superior way the operations of a lower power.
Ad 3. Every change (motus) presupposes something unchangeable. For when the change involves quality, the substance remains unchangeable. And when it is the substantial form that undergoes change, the matter remains unchangeable. Also, things that are changeable have unchangeable relationships (habitudines). For instance, even though Socrates is not always sitting, it is still unchangeably true that when he is sitting, he stays in one place. And for this reason nothing prevents us from having unchangeable knowledge of changeable things.°
Article 2. Does the soul understand bodies through
its essence or through species?
It seems that the soul understands bodies through its essence:
1. Augustine says in De trinitate X [v.7] that the soul "weaves together and seizes the images of bodies, images that have been made in itself, from itself. For it gives to them, in forming them, something of its own substance." But the soul understands bodies through their likenesses. Therefore it cognizes bodies through its essence, which it "gives to" such likenesses in forming them, and "from" which it forms them.
2. The Philosopher says in De anima III [431b21] that "the soul is in a certain way all things." Therefore, since like is cognized by like, it seems that the soul cognizes bodies through itself.
3. The soul is higher than bodily creatures. But lower things are in higher things in a more eminent way than they are in themselves, as Dionysius says. Therefore all bodily creatures exist in a loftier way in the soul's substance than in themselves. Therefore the soul can cognize bodily creatures through its substance.
On the contrary. Augustine says in De trinitate IX [iii.3] that "the mind gathers knowledge about bodily things through the body's senses." But the soul itself cannot be cognized through the body's senses. Therefore the soul does not cognize bodies through its substance.°
Reply. The ancient philosophers claimed that the soul cognizes bodies through its essence. For it was a general presupposition, in the minds of everyone, that like is cognized by like, and they further held that the form of the cognized thing is in the one cognizing in the very way it is in the thing cognized. The Platonists, however, argued for the opposite [of what the others maintained].° For Plato, since he recognized that the intellective soul is immaterial and cognizes immaterially, claimed that the forms of the things cognized subsist immaterially. Earlier natural philosophers, in contrast, since they held that the things cognized are bodily and material, claimed that those things must exist materially even in the soul that is cognizing. Accordingly, in order to attribute cognition of all things to the soul, they claimed that it has a nature common to all things. And because the nature of things formed out of principles is made up of those principles, they attributed to the soul the nature of a principle. Thus he who said that fire is the principle of all things claimed that the soul has the nature of fire, and likewise for air and water. But Empedocles, who claimed that there were four material elements and two moving elements, said that the soul is made up of these. Accordingly, since they claimed that things exist in the soul materially, they claimed that all of the soul's cognition is material, not distinguishing between intellect and sense.
This view can be disproved.
1. Things made up from a material principle (which is what they were discussing) exist in that principle only potentially. But something is cognized not insofar as it is in potentiality, but only insofar as it is in actuality (as is clear in Metaphysics IX [1051a22-33]). As a result, the potentiality itself is cognized only through actuality.° So therefore it would not suffice to attribute the nature of principles to the soul, in order for it to cognize all things, unless it were to contain the natures and forms of their individual effects, such as flesh, bones, and others of this sort. (This is how Aristotle argues against Empedocles in De anima I [409b25-10a13].)
2. If a thing cognized had to exist materially in the one cognizing, then there would be no reason why things that subsist materially outside of the soul would lack cognition. For instance, if the soul were to cognize fire through fire, then even the fire that is outside the soul would cognize fire.
We can conclude, then, that material things, when cognized, must exist in the one cognizing not materially, but instead immaterially. And the reason for this is that an act of cognition extends to things that are outside the one cognizing. For we cognize even those things that are outside us. But matter limits the form of a thing to one particular. Thus it is clear that the nature of cognition is inversely correlated with the nature of materiality. So things that only materially receive forms, like plants, are in no way cognitive, as is said in De anima II [424a32-b3]. But the more immaterially that something has the form of the thing cognized, the more perfectly it cognizes. This is why the intellect, which abstracts the species not only from matter, but also from its individual material conditions, cognizes more perfectly than does sense, which takes on the form of the thing cognized without the matter, of course, but along with the material conditions. And among the senses, sight is the most cognitive, because it is the least material, as was said above [78.3cxx]. And among intellects, the more immaterial that each one is, the more perfect it is.°
From all of this, then, it is clear that if there is some intellect that through its essence cognizes all things, its essence must have all things within itself, immaterially (just as the ancients posited that the essence of the soul was actually composed of the principles of all material things, so that it could cognize all things). But this is unique to God, that his essence contains all things immaterially, in the way that an effect preexists, virtually, in its cause. Therefore only God understands all things through his essence. The human soul does not, nor even does an angel.°
Ad 1. Augustine speaks there of an imaginary vision, which is brought about through the images of bodies. In forming these images, the soul does "give something of its own substance," as a subject is given so as to be informed by a form. And so it makes images of this sort "from itself," not that the soul or any part of the soul is converted to being this or that image, but in the way that a body is said to become something colored when it is informed by color. And this meaning is evident from what follows. For he says that "it serves something" (something not informed by such an image) "that freely judges the appearance of such images," and he says that "this is the mind" or intellect. As for the part that is informed by images of this sort (the imaginative part), he says that this is "common" to us and to beasts.
Ad 2. Aristotle did not claim that the soul is actually composed of all things, as the ancient natural philosophers did. Rather, he said that the soul is in a certain way all things, inasmuch as it is in potentiality for all things: for sensible things, through sense, and for intelligible things, through intellect.
Ad 3. Every creature has a finite and determinate existence. So the essence of a higher creature, even if it is somewhat like a lower creature insofar as they share a genus, is still not completely like it, because the species of the lower creature is outside the species that the higher creature is determined to. But the essence of God is a perfect likeness of all things, with respect to all things that are found in reality, as the universal principle of all things.
Article 3. Are the species of all intelligible things
naturally endowed to the soul?
It seems that the soul understands all things through species naturally endowed to it:
1. Gregory, in his homily on the ascension, says that human beings "have understanding in common with the angels." But the angels understand all things through naturally endowed forms. Thus it is said in the Liber de causis  that every intelligence is filled with forms. Therefore the soul also has the species of things endowed by nature, and with these it understands bodies.
2. The intellective soul is loftier than bodily prime matter. But prime matter was created by God beneath the forms it is in potentiality for. Therefore, a fortiori, the intellective soul was created by God beneath intelligible species. Accordingly, the soul understands bodies through naturally endowed species.
3. One can make a true reply only about that which one knows. But even someone without any education, having no acquired knowledge, makes a true reply about particular facts, if he is questioned in the right order. (Plato's Meno [82a-86b] describes doing this with someone.) Therefore someone has a cognition of things before he acquires the knowledge,° which would not be the case if the soul did not have naturally endowed species. So the soul understands bodies through naturally endowed species.
On the contrary. The Philosopher says in De anima III [430a1], speaking of the intellect, that it is "like a tablet on which nothing has been written."°
Reply. Since the principle of an action is a form, a thing must be related to the form that is the principle of its action in the same way that it is related to its action. For example, if a thing is moved upward because of being light, then what is only potentially lifted upward is only potentially light, whereas what is actually lifted upward is actually light. But we see, in the case of both sense and intellect, that a human being is sometimes only potentially cognizant. From this potentiality, one is brought to actuality (i) in sensing, through the actions of sensible things on the senses; (ii) in understanding, through instruction or discovery. So a cognitive soul must be said to be in potentiality both for the likenesses that are the principles of sensing and for the likenesses that are the principles of understanding. This is why Aristotle claimed that the intellect, with which the soul understands, does not have any naturally endowed species, but is initially in potentiality for all such species.
But sometimes, because of some impediment, that which actually has a form is unable to act in accord with that form ── as when something light is impeded from being lifted upward. On this basis, Plato claimed that the human intellect is naturally filled with all intelligible species, but is impeded by its union with the body, with the result that it cannot become actualized. But this claim does not seem acceptable:
· First, if the soul has a natural knowledge of all things, it does not seem possible that it should be made so forgetful of this natural knowledge as not to know that it has such knowledge. For no one forgets the things that he naturally cognizes, such as that every whole is greater than its part, and others of that sort.° This seems especially absurd if it is held to be natural to the soul to be united to its body, as was established above [76.1cΆ2]. For it is absurd that a thing's natural operation be entirely impeded by something natural to it.
· Second, the falseness of this view is clearly apparent from the fact that when one lacks a sense, one lacks knowledge of the things apprehended by that sense. Someone born blind, for example, can have no knowledge of colors. This would not be the case if the concepts (rationes) of all intelligible things were naturally endowed to the soul. And so it must be said that the soul does not cognize bodies through naturally endowed species.
Ad 1. Human beings do have understanding in common with the angels, but fall short of the eminence of their intellect ── just as lower bodies, which for Gregory merely exist, fall short of the existence of higher bodies. For the matter of lower bodies is not entirely completed by their forms, but is in potentiality for forms that it does not possess. The matter of the celestial bodies, in contrast, is entirely completed by their form, and so it is not in potentiality for another form, as was said above [66.2c]. Likewise, the intellect of an angel is perfected by intelligible species as part of its nature, whereas the human intellect is in potentiality for such species.
Ad 2. Prime matter has substantial existence through a form, and so it had to be created beneath some form ── otherwise it would not actually exist.° Still, what exists beneath one form is in potentiality for others. Intellect, in contrast, does not have substantial existence through an intelligible species, and so there is no comparison.
Ad 3. A series of questions asked in the proper order goes from common principles known per se to specific propositions. Such a process causes there to be knowledge in the soul of the one learning. So when someone gives a true reply to the questions he is subsequently asked, it is not that he grasped them beforehand, but because he is then learning them for the first time. For it makes no difference whether the person teaching goes from common principles to conclusions by making assertions or by asking questions. For, in each case, the mind of the one listening is made certain of the later propositions through the earlier ones.
Article 4. Do intelligible species emanate from
certain separate immaterial forms, into the soul?
It seems that intelligible species emanate from certain separate forms, into the soul:
1. Everything that is such through participation is caused by something that is essentially such ── something on fire, for instance, is traced back to fire as its cause.° But the intellective soul, inasmuch as it actually understands, participates in the intelligibles themselves, since the intellect, when actualized, in a certain way is the actualized object of intellect. Therefore the causes of the intellective soul's actually understanding are things that are in their own right, essentially, the actualized objects of intellect. But the essential actualized objects of intellect are forms existing without matter. Therefore the intelligible species by which the soul understands are caused by certain separate forms.
2. Intelligible things are related to intellect as sensible things to sense. But the causes of the sensible species that are in sense, by which we sense, are sensible things that are actual outside the soul. Therefore the intelligible species by which our intellect understands are caused by certain actually intelligible things that exist outside the soul. But the only things of this sort are forms separate from matter. Therefore the intelligible forms of our intellect emanate from certain separate substances.
3. Everything in potentiality is brought to actuality through that which is in actuality. Therefore if our intellect existed first in potentiality and later were actually to understand, this would have to be caused by an intellect that is always in actuality. But this is a separate intellect. Therefore the intelligible species by which we actually understand are caused by certain separate substances.
On the contrary. On this view we would not need the senses in order to understand. This is clearly false, above all because someone who lacks one of the senses can in no way have knowledge of the sensible qualities related to that sense.
Reply. Some have claimed that the intelligible species of our intellect come from certain separate forms or substances. There are two versions of this theory. Plato, as was said [79.3cxx, a1cxx], posited Forms of sensible things subsisting on their own (per se) without matter ── e.g., the Form of a human being, which he named Human Being per se, and the Form or Idea of a horse, which he named Horse per se, and so on in other cases. He claimed, then, that these separate Forms are participated in both by our soul and by corporeal matter: by our soul for cognition, and by corporeal matter for existence. So just as corporeal matter, by participating in the Idea of stone, is made this particular stone, so too our intellect, by participating in the Idea of stone, is made to understand stone. But participation in Ideas occurs through a likeness of that Idea in that which participates in it. (It is in this way that an exemplar is participated in by what it exemplifies.)° Therefore just as he claimed that sensible forms that are in corporeal matter emanate from Ideas as likenesses of them, so he claimed that the intelligible species of our intellect are likenesses of the Ideas from which they emanate. And for this reason, as was said above [84.1cxx], he made the sciences and definitions refer to Ideas.
But it is contrary to the nature (rationem) of sensible things for their forms to subsist without their matters, as Aristotle proves in a number of ways. Accordingly, Avicenna, after ruling out this view, posited not that the intelligible species of all sensible things subsist on their own without matter, but that they preexist immaterially in separated intellects. Such species are derived from the first of these separated intellects into the next one, and so on down to the final separated intellect, which he named the Agent Intellect. From this intellect, as he says, intelligible species emanate into our souls, and sensible forms into corporeal matter.
So Avicenna agrees with Plato that our intellect's intelligible species emanate from certain separate forms. But Plato says that these forms subsist on their own, whereas Avicenna locates them in an agent intelligence.° They also differ in that Avicenna holds that intelligible species do not remain in our intellect after it ceases to understand actually, but that it needs to turn once more to receive them anew. So he does not hold that knowledge is naturally endowed to the soul, as does Plato, who holds that our participation in the Ideas remains unchangeably in the soul.
But on this view no good reason can be provided for why our soul is united to its body. For it cannot be said that the intellective soul is united to its body for the sake of that body, since a form is not for the sake of its matter, nor a mover for the sake of what it moves, but rather conversely. But a body seems necessary for the intellective soul above all for its proper operation, which is to understand. For the soul does not depend on the body for its existence. But if the soul were naturally suited to receive intelligible species solely through an influx from certain separate principles, and if it did not take in species through the senses, then it would not need a body in order to understand and so it would be pointless for it to be united to its body.°
Now it might be said that our soul, in order to understand, does need the senses, which somehow arouse it to consider the things whose intelligible species it receives from the separated principles. But this does not seem adequate, because being aroused in this way seems necessary to the soul only inasmuch as it is stupefied, according to Platonists, and somehow made forgetful by its union with the body. So the senses would do nothing for the intellective soul other than removing the impediment that affected the soul because of its union with the body. Therefore the reason for the soul's union with its body remains to be found.
It might be said, however, in line with Avicenna, that the senses are necessary to the soul because they arouse it to turn toward the Agent Intelligence, from which it receives species. But this is not adequate. For if it belongs to the soul's nature to understand through species emanating from the Agent Intelligence, then it would follow that the soul could sometimes turn toward the Agent Intelligence out of the inclination of its own nature, or even that, aroused by one sense, it turns toward the Agent Intelligence to receive the species of sensibles belonging to a sense that the person does not have. In this way, someone born blind could have knowledge of colors, which is clearly false. Accordingly, it must be said that the intelligible species by which our soul understands do not emanate from separate forms.
Ad 1. The intelligible species that our intellect participates in are traced back, as to their first cause, to a principle that is essentially intelligible ── God. But they proceed from that principle by means of the forms of sensible and material things, from which we collect knowledge, as Dionysius says.
Ad 2. Material things, in virtue of the existence that they have outside the soul, can be actually sensible but not actually intelligible. So the cases of sense and intellect are not similar.
Ad 3. Our possible intellect is brought from potentiality to actuality through some actual being ── that is, through the agent intellect, which is a power that belongs to our soul, as was said [79.4]. It is not brought to actuality through some separated intellect serving as the proximate cause, though perhaps it is through one serving as the remote cause.
Article 5. Does our soul see all the things that it
understands in their eternal natures?
It seems that the intellective soul does not cognize material things in their eternal natures:°
1. That in which a thing is cognized is itself cognized better and in advance. But the human intellective soul, in its state of life at present, does not cognize eternal natures, because it does not cognize God himself, in whom the eternal natures exist. (The soul is instead joined to him as to the unknown, as Dionysius says in Mystical Theology 1.3.) Therefore the soul does not cognize all things in their eternal natures.
2. It is said in Romans 1.20, the invisible things of God are clearly seen through the things that have been made. But included among the invisible things of God are the eternal natures. Therefore the eternal natures are cognized through material creatures, not conversely.
3. Eternal natures are nothing other than ideas. For Augustine says in his book On 83 Questions  that ideas are the stable natures of things existing in the divine mind. So if it is said that the intellective soul cognizes all things in their eternal natures, then we are returning to the view of Plato, who held that all knowledge is derived from Ideas.
On the contrary is what Augustine says in Confessions XII [xxv.35]: "If we both see that what you say is true, and we both see that what I say is true, then where do we see that? Not I in you, nor you in me, but both of us in that unalterable truth that is above our minds." But unalterable truth is contained in the eternal natures. Therefore the intellective soul cognizes all true things in their eternal natures.
Reply. As Augustine says in On Christian Doctrine II [xl.60], "if the so-called philosophers happened to say anything true and befitting our faith, we should appropriate that for our own use, taking it from them as if they were its unjust possessor. For the teachings of the pagans contain a number of spurious and superstitious inventions, which each one of us who is leaving pagan society has to avoid." So Augustine, drenched as he was in the teachings of the Platonists, if he found anything in their words befitting the faith, he took it, whereas the things he found contrary to the faith he changed into something better. Now Plato, as was said above [84.1cxx, 84.4cxx], posited that the Forms of things subsist on their own (per se), separate from matter. He called these Ideas, and said that through participation in them our intellect cognizes all things. So just as corporeal matter is made to be a stone through participation in the Idea of Stone, so our intellect has a cognition of stone through participation in that same Idea. But it seems foreign to the faith that the forms of things should subsist on their own outside of things, without matter, in the way that the Platonists maintained, saying that Life per se or Wisdom per se are certain creative substances (as Dionysius says in Divine Names 11.6). So in place of these Ideas that Plato had introduced, Augustine posited in his book On 83 Questions  that the natures of all creatures exist in the divine mind; in virtue of these all things are formed and in virtue of these the human soul has cognition of all things.
So when one asks whether the human soul cognizes all things in their eternal natures, the reply should be that a thing is said to be cognized in something in two ways:
· First, in an object that is itself cognized, as someone sees in a mirror the things whose images are reflected in the mirror. In this way the soul, in its present state of life, cannot see all things in their eternal natures, whereas the blessed do in this way cognize all things in their eternal natures. They see God and see all things in God.
· Second, something is said to be cognized in something as in the source of the cognition ── as when we say that things are seen in the sun that are seen through the sun. And in this way it is necessary to say that the human soul does cognize all things in their eternal natures: we cognize all things through participation in these eternal natures. For the intellectual light that is in us is nothing other than a certain participating likeness of the uncreated light, in which the eternal natures are contained. Thus it is said in Psalm 4.6, Many say, Who shows us good things? To this question the Psalmist replies, saying The light of your face, Lord, is imprinted upon us. This is as if to say, through that seal of the divine light on us, all things are displayed to us.°
Still, in order to have knowledge about material things, we require, in addition to the intellectual light within us, intelligible species taken from things.° As a result, we do not have knowledge of material things solely through participation in their eternal natures, in the way that the Platonists held that mere participation in the Ideas suffices for having knowledge. Thus Augustine says in De trinitate IV [xvi.21], "Since the philosophers establish through the most certain proofs that all temporal things are brought about by their eternal natures, could they on that account perceive in these natures, or infer from these natures, how many kinds of animals there are, and what the origins are of each? Have they not sought all of these out through the history of places and times?"
That Augustine did not understand all things to be cognized in their eternal natures (or in the unalterable truth) in such a way that the eternal natures themselves are seen, is clear from what he himself says in On 83 Questions , that not each and every rational soul is asserted to be worthy of that vision (that is, a vision of the eternal natures) but only those that have been holy and pure ── as the souls of the blessed are.
From this the reply to the objections is clear.
Article 6. Does the soul acquire
intelligible cognition from sensation?
It seems that intellective cognition is not drawn from sensible things:
1. Augustine says in On 83 Questions  that pure truth should not be looked for from the senses of the body. He proves this in two ways. First, because everything that the bodily senses reach is changing without a moment's rest, and what does not remain still cannot be perceived. Second, because even when all of the things that we sense through the body are not present to the senses, we are nevertheless affected by images of them ── in dreams or delusions, for instance. But we are not able through the senses to distinguish whether we are sensing the sensible things themselves or false images of them, and nothing can be perceived that is not distinguished from what is false. So he concludes that the truth should not be looked for from the senses. But intellectual cognition apprehends the truth. Therefore intellectual cognition should not be looked for from the senses.
2. Augustine says in De Genesi ad litteram XII [xvi.33] that "one should not believe that a body produces something within a spirit, as if the spirit were subject to the producing body, in the place of matter. For that which produces is in every way more excellent than the thing from it produces something." Thus he concludes, "a body does not produce an image of a body in the spirit; rather, spirit does so in itself." Therefore intellectual cognition is not derived from sensible things.
3. An effect does not extend beyond the power of its cause. But intellectual cognition extends beyond sensible things: for we understand things that cannot be perceived by sensation. Therefore intellectual cognition is not derived from sensible things.
On the contrary. The Philosopher establishes in Metaphysics I [980a28-81a2] and at the end of the Posterior Analytics [100a3-14] that our cognition has its source in sensation.
Reply. Philosophers have held three views on this question. Democritus claimed that "there is no cause for any of our cognitions other than that images come from the bodies we are thinking about, and that they enter into our soul," as Augustine reports in his epistle to Dioscorus [118.4]. Aristotle too says in the De somno [464a5] that Democritus supposed cognition to occur through "images and emanations." The reason for this view was that both Democritus himself and other ancient natural philosophers did not claim that intellect differs from sense (as Aristotle says in the De anima [427a17-29]). As a result, since a sense receives an impression from something sensible, they held that all of our cognition comes entirely from an impression from sensible things. Democritus claimed that this impression occurs through the emanation of images.
Plato, in contrast, claimed that intellect differs from sense, and that the intellect is an immaterial power not using a bodily organ for its act. And because something bodily cannot make an impression on something nonbodily, he claimed that intellectual cognition is not brought about through an impression on intellect from sensible things, but through its participation in separate intelligible Forms, as was said [84.4cxx, 84.5cxx]. He also claimed that sense is a power operating on its own (per se): so not even sense itself, since it is a spiritual power, receives an impression from sensible things. Rather, the organs of the senses receive an impression from sensibles, and because of this impression, the soul is somehow aroused to form in itself the species of sensible things. Augustine also seems to come close to this view in De Genesi ad litteram XII [xxiv.51], where he says that "it is not the body that senses, but the soul through the body, using the body as a messenger in order to form within itself the message received on the outside." On Plato's view, then, it is true neither that intellectual cognition proceeds from the sensible, nor even that sensible cognition proceeds entirely from sensible things. Rather, sensible things arouse the sensory soul so that it senses, and likewise the senses arouse the intellective soul so that it understands.
Aristotle took the middle route. For he claimed, with Plato, that intellect differs from sense. But he denied that sense has a proper operation not shared with the body. As a result, sensing is the act not of the soul alone, but of the compound. And the same is true, he claimed, for all the operations of the sensory part. Therefore, since there is nothing unacceptable about sensible things outside the soul causing something within the compound,° Aristotle agreed with Democritus that the operations of the sensory part are caused by the impression of the sensibles on a sense ── not in the form of an emanation, as Democritus claimed, but through some kind of operation. (For Democritus claimed that all action occurs through an influx of atoms,° as is clear in De generatione I [324b25-25a2).
Aristotle claimed that the intellect, in contrast, has an operation that it does not share with the body. But nothing bodily can make an impression on something nonbodily. And so in order to cause an intellectual operation, it is not enough, on Aristotle's view, to have the impression of sensible bodies. Instead, something loftier is required, given that "that which acts is loftier than that which is acted on," as he says. But it is not that the intellectual operation is caused in us solely from the impression of certain higher things, as Plato claimed; rather, that higher and loftier agent that Aristotle calls the agent intellect (of which we have already spoken above [79.3-4]) makes phantasms drawn from the senses be actually intelligible, by way of a certain abstraction. So in this regard, intellectual operation is caused by sensation, in respect of phantasms. But because phantasms are not sufficient to make an impression on the possible intellect, but must be made actually intelligible through the agent intellect, it cannot be said that sensible cognition is the whole and complete cause of intellectual cognition, but rather in a certain way the material of the cause.
Ad 1. From those words of Augustine we are given to understand that truth is not entirely to be looked for from the senses. For we require the light of agent intellect, through which we unchangeably cognize the truth in changeable things, and we distinguish the things themselves from the likenesses of things.°
Ad 2. Augustine is speaking there not of intellectual cognition, but of imaginative. Now on Plato's view, the power of imagination has an operation that belongs to the soul alone. This is why° Augustine showed that bodies do not impress their likenesses on the power of imagination, and that the soul itself does this. He even used the same argument that Aristotle uses to prove that the agent intellect is something separate ── namely, that "that which acts is loftier than that which is acted on." And there is no doubt that on this view one must posit in the power of imagination not only a passive capacity but also an active one.
But if, in keeping with Aristotle's view, we hold that the action of the power of imagination belongs to the compound, then no difficulty follows. For a sensible body is loftier than the animal's organ inasmuch as it is related to the organ as an actual being to a potential being ── as something actually colored is related to the pupil, which is colored potentially.
Nevertheless, one could say that although the first impression on the power of imagination is brought about through the movement of sensible things (since phantasia is a movement made by sense, as is said in the De anima [429a1-2]), still there is a certain operation of the soul in a human being that forms various images of things by dividing and composing, even ones that are not drawn from the senses. And the words of Augustine can be understood in this way.
Ad 3. Sensory cognition is not the whole cause of intellectual cognition, and so it is not surprising if intellectual cognition extends beyond the sensory.
Article 7. Does the intellect need phantasms
in order actually to understand?
It seems that the intellect, through the intelligible species that it has within itself, can actually understand without turning toward phantasms:
1. The intellect is actualized through the intelligible species that informs it. But the intellect's being actualized is its very understanding. Therefore intelligible species suffice for the intellect to understand actually, without its turning toward phantasms.
2. Imagination depends on sense more than intellect depends on imagination. But imagination can actually imagine in the absence of anything sensible. Therefore, a fortiori, the intellect can actually understand without turning toward phantasms.
3. There are no phantasms of incorporeal things, because imagination does not transcend the temporal and continuous.° Therefore, if our intellect cannot actually understand anything without phantasms, it would follow that it could not understand anything incorporeal. This is clearly false, since we understand the truth itself, as well as God and angels.
On the contrary. The Philosopher says in De anima III [431a16-17] that "the soul understands nothing without a phantasm."
Reply. It is impossible for our intellect, in its present state of life (while connected to a body capable of being acted on),° actually to understand anything without turning toward phantasms. There are two indications that make this clear.
First, since the intellect is a power that does not use a corporeal organ, it would in no way be impeded in its act by damage to any corporeal organ, unless its act required the act of a capacity that uses a corporeal organ. But sense, imagination, and the other powers of the sensory part do use a corporeal organ. Consequently, it is clear that intellect's actually understanding ── not just taking in knowledge anew, but also using knowledge already acquired ── requires an act of imagination and of the other powers. For we see that when the power for imagination has its action impeded by damage to the organ (as happens to the phrenetic°), and likewise when the power for memory has its action impeded (as happens to the lethargic°), the person is impeded from actually understanding even the things he has already acquired knowledge of.
Second, everyone can experience within oneself that when one tries to understand something, one forms certain phantasms for oneself by way of examples, in which one examines, as it were, the thing one is striving to understand.° And so it is that even when we wish to make someone else understand a thing, we propose examples to him, through which he can form phantasms for himself in order to understand.
The reason this is so° is that a cognitive capacity is proportioned to what it cognizes.° As a result an angelic intellect, which is entirely separate from any body, has as its proper object an intelligible substance separate from body. Through such an object it cognizes material things. In contrast, the human intellect, which is connected to a body, has as its proper object a quiddity or nature existing in corporeal matter. Through such natures of visible things it rises even to some cognition of invisible things. By its definition (ratione), however, this nature exists in some individual, because it does not occur without corporeal matter. The nature of a stone, for example, is by definition in this stone; and the nature of a horse is by definition in this horse, and so forth. Accordingly, the nature of a stone, or of any material thing, cannot be completely and truly cognized except by being cognized as existing in a particular. But we apprehend the particular through sense and imagination. And so it is necessary, in order for intellect actually to understand its proper object, that it turn toward phantasms so as to examine the universal nature existing in the particular.
If, on the other hand, the proper object of our intellect were a separate form (or if the natures of sensible things were subsistent and not in particulars, as the Platonists held), then our intellect, in understanding, would not always have to turn toward phantasms.
Ad 1. The species preserved in the possible intellect exist there dispositionally when it is not actually understanding, as was said above [79.6]. So in order for us to understand actually, that preservation of species is not sufficient; rather, we must use those species as is appropriate for the things they are species of ── the natures existing in particulars.
Ad 2. The phantasm itself is also the likeness of a particular thing. As a result, imagination needs no other likeness of a particular, in the way that the intellect does.
Ad 3. Incorporeal things, of which there are no phantasms, are cognized by us through a comparison to sensible corporeal things, of which there are phantasms. So we understand the truth by considering the thing with reference to which we are looking into the truth. God, however, we cognize as a cause, and through the methods of exceeding and subtracting (as Dionysius says).° Also, in our present state of life, we can cognize other incorporeal substances only through subtracting, or through some comparison to corporeal things. Consequently, when we understand anything of that sort, we necessarily have to be turned toward phantasms of corporeal things, even though there are no phantasms of incorporeal things.
Article 8. Is the intellect's judgment impeded
by obstruction to the sensory powers?
It seems that the intellect's judgment is not impeded by obstruction to the senses:
1. That which is higher does not depend on something lower. But the intellect's judgment is higher than sense. Therefore the intellect's judgment is not impeded by obstruction to the senses.
2. Syllogizing is an act of intellect. But the senses are obstructed while one sleeps, as is said in the De somno [454b10]. Still, it does sometimes happen that a person syllogizes while sleeping. Therefore the intellect's judgment is not impeded by obstruction to the senses.
On the contrary. Illicit events that occur in sleep do not count as sins, as Augustine says in De Genesi ad litteram XII [xv.31]. But this would not be so if a human being, while asleep, had free use of reason and intellect. Therefore one's use of reason is impeded by obstruction to the senses.
Reply. As was said [84.7cxx], our intellect's proper, proportionate object is the nature of sensible things. But no complete judgment about a thing can be rendered unless all that pertains to that thing is cognized ── especially if one fails to grasp that which is the terminus and end of the judgment. But the Philosopher says in De caelo III [306a16-17] that just as the end of pragmatic knowledge is its use, so the end of natural knowledge is that which the senses see first. For a workman seeks to cognize a knife only for the sake of its use ── so as to use this particular knife. Likewise, a natural philosopher seeks to cognize the nature of a stone and a horse only so as to know the natures (rationes) of things seen by the senses. But it is clear that the workman cannot make a complete judgment about the knife if he doesn't know its use, and likewise with natural knowledge there can be no complete judgment about natural things if their sensible features are not known. But all the things we understand in our present state are cognized by us through a comparison to natural sensible things.° As a result, it is impossible for us to have complete intellectual judgment when there is an obstruction to the senses through which we cognize sensible things.
Ad 1. Although the intellect is higher than the senses, it still in a way receives from the senses, and its first and principal objects are grounded in sensible things. And so the intellect's judgment is necessarily impeded when the senses are obstructed.
Ad 2. The senses are obstructed in people who are asleep because of certain vapors and fumes that have been released, as is said in the De somno [456b17-28]. And so, depending on the condition of such vapors, the senses may be more or less obstructed. For when there is a great deal of motion on the part of the vapors, then not only the senses but also the imagination is obstructed, and so no phantasms appear. This especially occurs when someone begins to sleep after a lot of food and drink. If the motion of the vapors is relaxed just a little, then phantasms appear, but distorted and disorderly, as occurs in people with fevers. If the motion is calmed still more, then orderly phantasms appear. This tends to happen especially at the end of sleep, and in people who are sober and have a strong imagination. If the motion is moderate, then not only does the imagination remain free, but also the common sense itself is partly released, so that a person sometimes judges while sleeping that the things he is seeing are dreams, as if he were discerning between reality and likenesses of reality. Still, the common sense remains partly obstructed, and so although it distinguishes some likenesses from reality, it is always deceived in some respects. In this way, then, just as the senses and imagination are released while one sleeps, so too the judgment of intellect is freed. But it is not freed entirely: as a result, those who form syllogisms while sleeping always realize when awakened that they have gone wrong in some respect.
Question 85. How the intellect understands bodily things,
and in what order
Next we must consider how the intellect understands, and in what order. And here there are eight points of inquiry:
a1. Does our intellect understand by abstracting species from phantasms?
a2. Are the intelligible species abstracted from phantasms related to our intellect as that which is understood or as that by which something is understood?
a3. Does our intellect naturally understand the more universal first?
a4. Can our intellect think about more than one thing at the same time?
a5. Does our intellect's thinking occur through composition and division?
a6. Can the intellect err?
a7. Can one person understand the same thing better than another?
a8. Does our intellect cognize the indivisible prior to the divisible?
Article 1. Does our intellect understand
by abstracting species from phantasms?
It seems that our intellect does not understand bodily and material things through abstraction from phantasms:
1. Any intellect that understands a thing otherwise than it is is false. But the forms of material things do not exist abstracted from the particulars that phantasms are likenesses of. Therefore if we understand material things by abstracting species from phantasms, there will be falseness in our intellect.
2. Material things are natural things, which contain matter in their definition. But nothing can be understood without what is contained in its definition. Therefore material things cannot be understood without matter. But matter is the principle of individuation. Therefore material things cannot be understood by abstracting the universal from the particular, which is to abstract intelligible species from phantasms.°
3. It is said in De anima III [431a14-15] that phantasms are related to the intellective soul as colors are related to sight. But sight occurs not through the abstraction of certain species from colors, but through the colors' making an impression on sight. Therefore understanding comes about not through something's being abstracted from phantasms, but through the phantasms' making an impression on intellect.
4. As is said in De anima III [430a13-15], the intellective soul has two components, the possible and the agent intellect. But abstracting intelligible species from phantasms is not the role of the possible intellect: it receives species already abstracted. Neither does abstraction seem to be the role of the agent intellect: it is related to phantasms as light is to colors, and light does not abstract anything from colors, but instead issues toward them. Therefore there is no way in which we understand by abstracting from phantasms.
5. The Philosopher says in De anima III [431b2] that the intellect "understands species in phantasms," and therefore not by abstracting species from phantasms.
On the contrary. It is said in De anima III [429b21-22] that "as things are separable from matter, so do they concern intellect." Therefore it must be that material things are understood to the extent that they are abstracted from matter and from material likenesses, which are phantasms.
Reply. As was said above [84.7cxx], the object of cognition is proportioned to the cognitive power. There are, however, three levels of cognitive powers. One kind of cognitive power, sense, is the actuality of a bodily organ, and so the object of any sensory capacity is a form as it exists in bodily matter. And because this sort of matter is the principle of individuation, every capacity of the sensory part is cognitive of particulars only. There is another kind of cognitive power that is neither the actuality of a bodily organ, nor in any way connected to bodily matter ── this is what an angelic intellect is. So the object of this cognitive power is a form subsisting without matter.° For even if angels cognize material things, still this is so only if they intuit them in immaterial things ── either in themselves or in God.
The human intellect falls in between. For as is clear from things said above, it is not the act of any organ [75.2], but yet it is one of the powers of the soul [79.1], which is the form of a body [76.1]. And so it is proper to it to cognize a form existing individually in bodily matter, but not as it is in such matter. But to cognize that which is in individual matter, not as it is in such matter, is to abstract the form from the individual matter that the phantasms represent. And so it is necessary to say that our intellect understands material things by abstracting from phantasms. And through material things considered in this way we come to some degree of cognition of immaterial things ── just as, conversely, angels cognize material things through immaterial things.
Plato, however, focusing only on the immateriality of the human intellect, and not on the fact that it is in some way united to a body, claimed that separated Ideas are the object of intellect, and that we understand not by abstracting, but rather by participating in abstract things, as was said above [84.4c].
Ad 1. Abstracting takes place in two ways. First, by way of composition and division, as when we understand something not to be in another or to be separated from it. Second, by way of a simple and unconditioned consideration, as when we understand one thing while not considering the other at all. So to abstract through intellect things that are not abstract in reality ── by abstracting in the first way ── is not without falseness. But there is nothing false in the second way of abstracting through intellect things that are not abstract in reality, as is clearly apparent in sensory cases. For if we understand or say that a color is not present in a colored body, or is separate from it, there will be falseness in the opinion or the statement. If, on the other hand, we consider the color and its characteristics, considering the colored apple not at all, or even if we verbally express what we understand in this way, there will be nothing false in the opinion and statement. For the apple is not part of the nature (ratione) of the color, and so nothing prevents one from understanding the color while understanding nothing about the apple. Likewise, I say that what pertains to the nature of the species of any material thing (of a stone, a human being, or a horse, for example) can be considered without the individual principles, which do not belong to the nature of the species. And this is to abstract the universal from the particular, or an intelligible species from phantasms: to consider the nature (naturam) of the species without considering the individual principles that are represented by the phantasms.
Therefore, when it is said that an intellect that understands a thing otherwise than it is is false, this is true if `otherwise' refers to the thing being understood. For the intellect is false when it understands a thing to be otherwise than it is. Thus the intellect would be false if it were to abstract the stone's species from matter in such a way as to understand it not to be in matter (as Plato claimed). But the assertion is not true if `otherwise' is taken with reference to that which understands. For there is nothing false in one's having a manner of understanding that differs from the thing's manner of being. For that which is understood exists in that which understands immaterially (in the manner of intellect) rather than materially (in the manner of a material thing).
Ad 2. Some claimed that the species of a natural thing is its form alone, and that the matter is not part of the species. But on this view, matter would not be included in the definitions of natural things. So we should say instead that there are two kinds of matter: common matter and signate or individual matter. Common matter is, for instance, flesh and bones, whereas individual matter is this flesh and these bones. Therefore the intellect abstracts the species of a natural thing from sensible individual matter, but not from sensible common matter. It abstracts the species of a human being, for instance, from this flesh and these bones, which do not belong to the nature of the species but are parts of the individual (as is said in Metaphysics VII [1035b28-1036a11]) and so [the species] can be considered without them. But the intellect cannot abstract the species of a human being from flesh and bones.
Intellect can abstract mathematical species from sensible matter ── not just from individual but also from common sensible matter. Yet it cannot abstract from common intelligible matter, but only from individual intelligible matter. For sensible matter is said to be bodily matter as it underlies sensible qualities such as hot and cold, hard and soft, etc. Intelligible matter, on the other hand, is said to be the substance as it underlies quantity. But it is clear that quantity is in the substance before the sensible qualities are.° As a result, quantities such as numbers and dimensions, and also shapes (which are the limits of quantities) can be considered without their sensible qualities, which is for them to be abstracted from sensible matter. But they cannot be considered without understanding the substance underlying the quantity, which would be for them to be abstracted from common intelligible matter. Still, they can be considered without this or that substance, which is for them to be abstracted from individual intelligible matter.
Now there are some [species] that can be abstracted even from common intelligible matter, such as being, one, potentiality and actuality, and others of this sort. These can exist without any matter at all, as is clear in immaterial substances. And because Plato did not consider what was said [ad 1] about the two ways of abstracting, he claimed that all the things we have said are abstracted by intellect are abstract in reality.
Ad 3. Colors, as they are in individual bodily matter, have the same manner of existence as does the visual capacity, and so they can impress their likeness on sight. But phantasms, since they are the likenesses of individuals, and exist in bodily organs, do not have the same manner of existence that the human intellect has, as is clear from what has been said [cxx]. So they cannot, through their own power, make an impression on the possible intellect. But through the power of the agent intellect a certain likeness occurs in the possible intellect, as a result of the agent intellect's turning toward the phantasms; this likeness represents what the phantasms represent only with respect to the nature of the species. And in this way an intelligible species is said to be abstracted from phantasms. It is not that numerically the same form that once was in the phantasms is later made in the possible intellect, in the way that a body is taken from one place and transferred to another.
Ad 4. Phantasms are both illuminated by the agent intellect and also, from them, through the power of the agent intellect, intelligible species are abstracted. They are illuminated, because just as the sensory part is made more powerful by its connection to the intellective part, so phantasms, through the power of the agent intellect, are made ready to have intelligible concepts abstracted from them. The agent intellect abstracts intelligible species from phantasms insofar as through the power of the agent intellect we can take into our consideration the natures of the species without the individual conditions. These likenesses inform the possible intellect.
Ad 5. Our intellect both abstracts intelligible species from phantasms, inasmuch as it considers the natures of things universally, and yet it also understands those natures in phantasms, because it cannot understand even the things whose species it abstracts, except by turning toward phantasms, as was said above [84.7].
Article 2. Are the intelligible species abstracted from phantasms
related to our intellect as that which is understood
or as that by which something is understood?
It seems that intelligible species abstracted from phantasms are related to our intellect as that which is understood:
1. That which is actually understood is within that which understands, because what is actually understood is the actualized intellect itself. But of the thing understood all that is within the actually understanding intellect is the abstracted intelligible species. Therefore such a species is the very thing actually understood.
2. What is actually understood must exist within something ── otherwise it would be nothing. But it does not exist within the thing that is outside the soul, because the thing outside the soul is material, and so nothing that is in it can be actually understood. It follows, therefore, that what is actually understood exists within the intellect, and so is nothing other than the intelligible species in question.
3. The Philosopher says in Perihermenias I [16a3] that spoken words "are symbols of states in the soul." But spoken words signify the things that are understood: for with a spoken word we signify that which we understand. Therefore these states of the soul, intelligible species, are the things that are actually understood.
On the contrary, an intelligible species is related to intellect just as a sensible species is related to sense. But a sensible species is not that which is sensed, but rather that by which sense senses.° Therefore an intelligible species is not that which is actually understood, but that by which the intellect understands.
Reply. Some have claimed that the cognitive powers in us cognize nothing other than their own states° ── for example, that a sense senses nothing other than the state of its organ. On this view, the intellect understands nothing other than its own state ── that is, the intelligible species received in it. Also, on this view such a species is the very thing that is understood. But this view is clearly revealed to be false in two ways.
· First, because the things we understand are the same as what knowledge (scientiae) is concerned with. So if the things that we understand were only species in the soul, then it would follow that all knowledge would concern only the intelligible species in the soul, rather than things outside the soul (just as, according to the Platonists, all knowledge concerns Ideas, which they claimed to be actually understood).
· Second, because the error would follow of those ancients who said that everything that seems is true, and that therefore contradictory claims might be true at the same time. For if a capacity cognizes nothing other than its own state, then it judges that alone. But how a thing seems is determined by how the cognitive capacity is affected. Therefore a cognitive capacity's judgment will always concern that which it judges, its own state, according to the way it is. Hence every judgment will be true. For example, if taste senses only its own state, then when someone with a healthy sense of taste judges that honey is sweet, he will be judging truly. Likewise, if someone who has an infected sense of taste judges that honey is bitter, he will be judging truly. For each one judges according to how his own sense of taste is affected. And so it follows that every opinion will be equally true and, more generally, so will every assent.
And so it should be said that an intelligible species is related to the intellect as that by which the intellect understands. The following makes this clear:°
Action is of two kinds (as is said in Metaphysics IX [1050a23-b2]):
· one that remains in the agent, like seeing and understanding;
· one that passes into external things, like heating and cutting.
Each occurs in virtue of some form. An action reaching toward an external thing occurs in virtue of a form that is a likeness of the action's object. The heat of the thing heating, for instance, is a likeness of the thing heated. Likewise, an action remaining in the agent occurs in virtue of a form that is a likeness of its object. So the likeness of a visible thing is that in virtue of which sight sees, and the likeness of the thing that is understood, an intelligible species, is the form in virtue of which the intellect understands.
But when the intellect reflects on itself it understands, in virtue of the same reflection, both its own understanding and the species by which it understands. And in this way the intellective species is secondarily that which is understood. But that which is understood first is the thing that the intelligible species is a likeness of.
This is clear even on the view of the ancients, who claimed that like is cognized by like. For they claimed that the soul, through the earth that is in it, cognizes the earth that is outside of it, and so on in other cases. Therefore, if we postulate a species of earth in place of earth (in keeping with the doctrine of Aristotle, who said that "it is not the stone that is in the soul, but a species of the stone"), then it will follow that the soul, through intelligible species, cognizes things that are outside of it.
Ad 1. That which is understood is within that which understands through its likeness. And the saying that "what is actually understood is the actualized intellect" holds in this way: insofar as a likeness of the thing understood is the intellect's form. (Similarly, a likeness of a sensible thing is the form of the actualized sense.) Accordingly, it does not follow that an abstracted intelligible species is that which is actually understood, but that it is a likeness of that.
Ad 2. Two things are implied when one speaks of that which is actually understood: namely, the thing that is understood, and the fact of its being understood. Likewise, when one speaks of an abstracted universal, two things are meant: namely, the very nature of a thing, and the abstraction or universality. Therefore, the nature that is in fact being understood or abstracted, or to which the intention of universality° applies, exists only in singular things. But its being understood or abstracted, or the intention of universality, exists within intellect.
We can see this through a comparison in the sensory case. For sight sees the color of an apple without its smell. So if one asks where the color is that is seen without the smell, it is clear that the color that is seen exists only in the apple. But its being perceived without the smell holds of it due to sight, inasmuch as sight has a likeness of the color and not the smell. Likewise, the humanity that is understood exists only in this human being or in that one. But the fact that this understood humanity is apprehended without individual conditions, which is for it to be abstracted, and from which an intention of universality follows, this holds of humanity insofar as it is perceived by intellect, in which there is a likeness of the nature of the species and not of the individual principles.
Ad 3. There are two operations in the sensory part. One occurs solely in virtue of an impression; in this way the operation of a sense is completed by its receiving an impression from something sensible. The other operation is the forming by which the imaginary power forms for itself an image of an absent thing, or even of something never seen. These two operations are combined within intellect. For we can first consider the possible intellect's being affected insofar as it is informed by an intelligible species. Once formed by this species, it secondly forms either a definition or a division or composition, which is signified through a spoken word. And so the account that a name signifies is the definition, and a statement signifies the composition and division of intellect. Therefore spoken words signify not the intelligible species themselves, but the things that the intellect forms for itself,° in order to make judgments about external things.
Article 3. Does our intellect naturally understand
the more universal first?
It seems that more universal things are not prior in our intellectual cognition:
1. Those that are prior and better known by nature are secondary (posteriora) and less well known relative to us. But universals are prior by nature, because the prior is that for which "the implication of being does not hold reciprocally."° Therefore universals are secondary in our intellect's cognition.
2. Composite things are prior to simple things, for us. But universals are more simple. Therefore, for us, they are known secondarily.
3. The Philosopher says in Physics I [184b11-14] that the thing defined falls under our cognition before the parts of the definition do. But more universal things are parts of the definition of less universal things, as animal is part of the definition of human being. Therefore, for us, universals are known secondarily.
4. We reach causes and principles through effects. But universals are principles of a sort. Therefore, for us, universals are known secondarily.
On the contrary. It is said in Physics I [184a23] that one has to arrive at singulars through universals.
Reply. There are two things that should be recognized with regard to our intellect's cognition. First, intellective cognition somehow gets its start from sensory cognition. And because the senses concern singulars, whereas the intellect concerns universals, it is necessary, for us, that the cognition of singulars comes before the cognition of universals. Second, one should recognize that our intellect goes from potentiality to actuality. But everything that goes from potentiality to actuality attains an incomplete actuality, in between potentiality and actuality, before attaining perfect actuality. But the perfect actuality that the intellect reaches is complete knowledge, through which things are cognized distinctly and determinately. Its incomplete actuality, on the other hand, is imperfect knowledge, through which things are known indistinctly, under a certain confusion.° For what is cognized in this way is in a certain respect actually cognized, and in a way it is potentially cognized. Thus the Philosopher says in Physics I [184a22-23] that "confused things are more clear and certain to us first, whereas secondarily" we cognize by distinctly distinguishing "principles and elements."
It is clear, however, that to cognize something in which many are contained, without having a specific grasp of any one of the things contained in it, is to cognize something under some confusion. And in this way one can cognize both a universal whole, in which the parts are contained in potentiality, and an integral whole. For each whole can be cognized in some confusion, without the parts being distinctly cognized. But to cognize distinctly that which is contained in the universal whole is to have a cognition of a less common thing ── just as to cognize an animal indistinctly is to cognize the animal inasmuch as it is an animal, whereas to cognize the animal distinctly is to cognize it inasmuch as it is a rational or nonrational animal, which is to cognize a human being or a lion. Therefore, for our intellect, cognizing an animal comes before cognizing a human being, and the same reasoning holds if we compare anything more universal to something less universal.
And because the senses go from potentiality to actuality just as the intellect does, the same order of cognition is apparent in the senses too.° For we make a sensory judgment about the more common before the less common, with respect to both location and time. This holds with respect to location when, for example, an object is seen from a distance. The object is perceived as a body before being perceived as an animal, and an animal before a human being, and a human being before Socrates or Plato.° It also holds with respect to time. For a boy at first distinguishes humans from non-humans before distinguishing this human being from another one. Thus "a boy at first calls all men his father, whereas later he discerns each one," as is said in Physics I [184b12-14].
The reason for this is clear.° For someone who knows something indistinctly knows the basis of the distinction [only] potentially as yet. Someone who knows the genus, for example, [only] potentially knows the differentia. And thus it is clear that indistinct cognition is midway between potentiality and actuality. So it should be said that, for us, the cognition of singulars comes before the cognition of universals, just as sensory cognition comes before intellective. But with respect to both sense and intellect, more common cognition comes before less common cognition.
Ad 1. A universal can be considered in two ways. First, inasmuch as the universal nature is considered at the same time as the intention of universality. And since the intention of universality (namely, that one and the same thing has a relationship with many) comes from the abstraction of intellect, it must be that in this way the universal is secondary. Thus it is said in De anima I [402b7-8] that "the universal animal is either nothing or is secondary." But according to Plato, who posited subsistent universals, the universal considered in this way would be prior to particulars, which according to him exist only through participation in subsistent universals, which are called Ideas.
In the second way, a universal can be considered with respect to its very nature (e.g., animality, humanity) as it is found in particulars. In accord with this, it should be said that nature has two kinds of order. First, in terms of the course of generation and time. In these terms, those that are incomplete and potential are prior. And in this way the more common is prior by nature, as is clearly evident in the generation of a human being and an animal: for an animal is generated before a human being is,° as is said in On the Generation of Animals [736b2-4]. The second order is that of completeness, or of nature's aim. Here actuality is unconditionally prior by nature to potentiality, and the complete is prior to the incomplete. And in this way, the less common is prior by nature to the more common, as human being is prior to animal. For nature's aim does not stop with the generation of an animal; its aim is to generate a human being.
Ad 2. A more common universal is related to a less common one as a whole and as a part:
· as a whole, inasmuch as the more universal contains potentially not only the less universal, but other things as well (contained under animal, for example, is not only human being, but also horse);
· as a part, inasmuch as the less common contains in its defining account not only the more common, but other things as well (a human being, for example, is not only an animal, but also rational).
In this way, then, animal considered in itself is prior in our cognition to human being, but human being is prior in our cognition to the fact that animal is part of its defining account.
Ad 3. A part can be cognized in two ways. In one way unconditionally, as it is in itself, and in this way nothing prevents the parts from being cognized before the whole ── stones, for example, before the house. In a second way, as they are parts of this whole, and in this way it is necessary for us to cognize the whole before the parts. For we cognize the house through a confused cognition before distinguishing its individual parts. So in this way it should be said that the parts of the definition, considered unconditionally, are known before what is defined; otherwise the thing being defined would not be made known through them. But inasmuch as they are parts of the definition, they are known secondarily. For we have a confused cognition of human being before we know how to distinguish all of what belongs to the defining account of human being.
Ad 4. The universal, taken with the intention of universality, certainly is in a way a principle of cognizing, to the extent that the intention of universality is a consequence of the mode of understanding that occurs through abstraction. But it is not necessary that everything that is a principle of cognizing is a principle of being, in the way that Plato supposed. For sometimes we cognize a cause through its effect, and a substance through its accidents. So a universal, taken in this way, is not on Aristotle's view a principle of being, nor a substance, as is clear in Metaphysics VII [1038b8-41a5].
But if we consider the nature of the genus and species as it is in singular things, then in a way it has the character of a formal principle with respect to singulars. For a thing is singular on account of its matter, whereas the defining account of the species is derived from the form. But the nature of the genus is related to the nature of the species more as a material principle: for the nature of the genus is derived from what is material in the thing, whereas the defining account of the species is derived from what is formal. (The defining account of animal, for example, is derived from its sensory capacity, whereas the defining account of human being is derived from its intellective capacity.) And so it is that nature's ultimate aim concerns the species and not the individual or the genus: for the form is the end of generation, whereas the matter is for the sake of the form.
Still, it need not be that the cognition of every cause or principle is secondary for us. For sometimes we cognize unknown effects through sensible causes, whereas sometimes we do the opposite.°
Article 4. Can our intellect think about
more than one thing at the same time?
It seems that we can think about more than one thing at the same time:
1. The intellect is above time. But before and after involve time. Therefore the intellect does not think about different things as before and after; it thinks about them at the same time.
2. Nothing prevents different forms that are not opposites from actually being within the same object at the same time. An apple, for instance, has both smell and color. But intelligible species are not opposites. Therefore nothing prevents one intellect from being actualized at the same time by different intelligible species. As a result, it can think about more than one thing at the same time.
3. The intellect thinks about a whole, such as a human being or a house, at the same time. But every whole contains more than one part. Therefore the intellect thinks about more than one thing at the same time.
4. The difference between one thing and another cannot be cognized unless each is apprehended at the same time, as is said in the De anima [426b23-24], and the same reasoning holds for any other relationship. But our intellect cognizes the difference and relationship between one thing and another. Therefore it cognizes more than one thing at the same time.
On the contrary. It is said in the Topics [114b34-35] that we think about one thing only, whereas we know more than one thing.°
Reply. The intellect can think about more than one thing by way of one thing, but not by way of more than one thing. In saying "by way of one or more things," I mean by one or several intelligible species. For the way that any action occurs depends on the form that is the principle of the action. So whatever an intellect can think about under a single species, it can think about at the same time. Thus God sees all things at the same time, because he sees all things through one thing, his essence. Whatever an intellect thinks about through distinct species, however, it does not think about at the same time. The reason for this is that it is impossible for the same subject to be perfected at the same time by several forms of a single genus and different species ── just as it is impossible for the same body to be colored at the same time, in the same place, by different colors, or to be shaped in different shapes. But all intelligible species belong to a single genus, because they are perfections of a single intellective capacity, even though the things that they are species of belong to distinct genera. Therefore it is impossible for the same intellect to be perfected at the same time by different intelligible species, so that it actually thinks about different things.
Ad 1. The intellect is above the time that is the number of the motion of corporeal things.° But the very plurality of intelligible species causes a fluctuation in its intelligible operations, in virtue of which one operation comes before another. Augustine calls this fluctuation time: for he says in De Genesi ad litteram VIII [xxii.43] that "God moves a spiritual creature through time."
Ad 2. It is not only opposite forms that cannot exist at the same time in the same subject, but also any forms of the same genus, even though they are not opposites. This is clear in the above example of colors and shapes [cxx].
Ad 3. Parts can be thought of in two ways. First, under some confusion, as they are in the whole, and in this way they are cognized through a single form of the whole, and so are cognized at the same time. Second, by a distinct cognition, inasmuch as each is cognized through its own species. In this way they are not thought of at the same time.
Ad 4. When the intellect thinks about the difference or relationship of one thing to another, it cognizes each of the things differentiated or related under the aspect of that relationship or difference. Thus it cognizes parts under the aspect of the whole, as was said [ad 3].
Article 5. Does our intellect's thinking
occur through composition and division?
It seems that our intellect's thinking does not occur through composition and division:
1. There is composition and division only of more than one thing. But the intellect cannot think about more than one thing at the same time. Therefore its thinking cannot occur through composition and division.
2. Every composition or division has some time attached to it, either present, past, or future.° But the intellect abstracts from time, as it also does from other particular conditions. Therefore the intellect's thinking cannot occur through composition and division.
3. The intellect thinks by becoming like things. But composition and division are nothing in reality, because nothing is found in reality except for the thing that is signified by the predicate and the subject, and this is one and the same thing, if the composition is true. For the human being is truly that which the animal is.° Therefore the intellect does not compose and divide.
On the contrary, spoken words signify the conceptions of intellect, as the Philosopher says in Perihermenias I [16a3-4]. But there is composition and division in spoken words, as is clear in the case of affirmative and negative propositions. Therefore the intellect composes and divides.
Reply. The human intellect's thinking must necessarily occur through composition and division. For since the human intellect goes from potentiality to actuality, it bears some likeness to things that undergo generation without immediately taking on their complete perfection, but by acquiring it successively.° Likewise, the human intellect does not immediately, in its first apprehension, acquire a complete cognition of a thing; instead, it first apprehends something about it, namely the quiddity of that thing, which is the first and proper object of intellect, and then it thinks about the proper attributes, accidents, and dispositions surrounding the thing's essence. Because of this, it must necessarily compose and divide one thing that it has apprehended with another, and it must go from one composition or division to another, which is to use reason.
Angelic and divine intellects, on the other hand, are like incorruptible things that have their complete perfection immediately from the start.° And so angelic and divine intellects immediately have a perfectly complete cognition of a thing, and so in cognizing the thing's quiddity, they cognize at once whatever we can cognize of the thing through composition and division and reasoning. And so the human intellect cognizes through composition and division, and likewise through reasoning, whereas the divine and angelic intellects cognize composition and division and reasoning, yet not by composing and dividing and reasoning, but rather through the intellection of a simple quiddity.
Ad 1. The intellect's composition or division takes place in virtue of some difference or relationship. And so the intellect cognizes more than one thing through composition and division, by cognizing the difference or relationship between things.
Ad 2. As was said above, the intellect abstracts from phantasms [85.1] and yet does not actually understand except by turning toward phantasms [84.7]. And as the intellect turns toward phantasms, so on that basis its composition or division has time attached to it.
Ad 3. A thing's likeness is received in intellect in keeping with the mode of intellect, not in keeping with the mode of the thing. Hence something on the side of the thing corresponds to the intellect's composition and division, but the way it is in the thing is not the way it is in intellect. For the proper object of the human intellect is the quiddity of a material thing, which falls under sense and imagination. But a material thing contains two sorts of composition.
1. Form to matter. Corresponding to this is the composition of intellect by which a universal whole is predicated of its part. For the genus is taken from the common matter, the differentia that completes the species is taken from the form, and the particular is taken from the individual matter.
2. Accident to subject. Corresponding to this real composition is the composition of intellect in virtue of which an accident is predicated of its subject (as when one says the human being is white).
But the composition of intellect differs from the composition of a thing, because those that are composed in the thing are distinct, whereas the intellect's composition signals the identity of the things composed. For  the intellect does not compose in such a way as to say that the human being is whiteness, but rather that the human being is white ── i.e., has whiteness. But that which is the human being is the same in subject as that which has whiteness. Something similar is true for  the composition of form and matter. For animal signifies that which has a sensory nature, whereas rational signifies that which has an intellective nature, human being that which has both, and Socrates that which has all of these, along with individual matter. It is in terms of this notion (rationem) of identity that our intellect, by predication, composes one thing with another.
Article 6. Can the intellect err?
It seems that the intellect can be false:
1. The Philosopher says in Metaphysics VI [1027b25-27] that "true and false are in the mind." But mind and intellect are the same, as was said above [79.8sc]. Therefore there is falseness in intellect.
2. Opinion and reasoning pertain to intellect. But falseness is found in each of these. Therefore there can be falseness in intellect.
3. There is sin in the intellective part. But sin comes with falseness, since those who do wrong are in error, as is said in Proverbs 14.22. Therefore falseness can be in intellect.
On the contrary. Augustine says in On 83 Questions  that "anyone with a false belief does not understand the thing he has a false belief about."° And the Philosopher says in the De anima [433a26] that "the intellect is always right."
Reply. In De anima III [430b29-31], the Philosopher compares intellect to sense as follows. Sense is not deceived about its proper object (sight, for example, about color), unless perhaps accidentally, by an impediment to the organ, as when the taste of those who are feverish judges sweet things to be bitter because of their tongues' being full of the wrong humors. Sense is deceived, however, about common sensibles, as in judging about size and shape. It judges that the sun is one foot wide, for instance, when in fact it is larger than the earth. And it is even more deceived about per accidens sensibles, as when it judges that gall° is honey because of the similarity in color. The reason for this is obvious. For any capacity, considered as that sort of capacity, is directed per se to its proper object. But such things always stand to one another in the same way.° So as long as the capacity remains, its judgment about its proper object will not fail.
The intellect's proper object is the quiddity of a thing. So the intellect is not false (non fallitur), speaking per se, with respect to the quiddity of a thing.° But the intellect can be false with respect to what surrounds the thing's essence or quiddity, when it orders one thing to another, either through composition or division or else through reasoning. Accordingly, it also cannot err about those propositions that are immediately cognized when the quiddity of their terms is cognized, as is the case for first principles. There is also infallible truth, in keeping with the certainty of the science, with respect to the conclusions reached through these principles.
Per accidens, however, the intellect can be deceived about quiddities in composite things° ── not due to [an impediment in] any organ, since the intellect is not a power that uses an organ, but due to composition entering into the definition, either when the definition of one thing is false for another (as the definition of a circle, for a triangle), or when a definition is false in itself because it implies an impossible composition (for instance, if winged rational animal were taken as the definition of a thing). So we cannot be deceived in the case of simple things, into whose definition composition cannot enter. But we do fail in entirely not attaining, as is said in Metaphysics IX [1051b25-33].
Ad 1. The Philosopher says that falseness is in the mind in virtue of composition and division.
The same should be said ad 2, for opinion and reasoning, and ad 3, for the error of those who sin, which consists in attaching oneself to the object of one's appetite. But the intellect is never deceived in its unconditioned consideration of a thing's quiddity and the things cognized through it. And this is what the authorities cited in the sed contra say.
Article 7. Can one person understand
the same thing better than another?
It seems that one person cannot understand one and the same thing better than another:
1. Augustine says, in his book On 83 Questions , "whoever understands a thing other than as it is does not understand it.... Undoubtedly, then, there is a perfect understanding, which nothing can surpass, and so the understanding of any given thing does not go on to infinity, nor can one person understand it more than another can."
2. The intellect, in understanding, is true. But truth, since it is a kind of equality between intellect and thing, does not admit of more and less, since a thing is not properly said to be more and less equal. Therefore neither is something said to be understood more and less.
3. The intellect is that which is most formal in a human being. But a difference in form causes a difference in species. Therefore if one human being understands more than another, it seems that they do not belong to a single species.
On the contrary. Experience shows that some understand more deeply than others. Someone who can reduce a conclusion to its first principles and first causes, for example, understands more deeply than someone who can reduce it only to its proximate causes.
Reply. There are two ways of understanding the claim that someone understands one and the same thing more than another does. In one way, `more' can be understood as governing the act of understanding with regard to the thing cognized. In this sense one person cannot understand the same thing more than another. For if he were to understand it otherwise than it is, whether better or worse, then he would be deceived and would not be understanding [it], as Augustine argues.
In another way, `more' can be understood as governing the act of understanding with regard to the one who is understanding. In this sense one person can understand the same thing better than another, because he has a greater power for understanding. (Similarly, someone sees a thing better through corporeal sight who has a more perfect power, in whom the visual power is more perfect.) In the case of intellect this occurs in two ways:
· First, with regard to an intellect that is itself stronger. For it is clear that the better the body's disposition, the better a soul it takes on. This is clearly apparent in things that differ in species. The reason for it is that actuality and form are received in matter in keeping with the capacity of the matter. So since, even among human beings, some have better disposed bodies, they take on a soul that has a greater power for understanding.° (This is why it is said in De anima II [421a26] that we see "those with soft flesh are mentally well fit.")
· This happens in another way with regard to the lower powers that the intellect needs for its operation. For those whose imaginative, cogitative, and memory powers are better disposed are themselves better disposed for understanding.°
The solution ad 1 is clear from what has been said, and likewise ad 2, since the truth of intellect consists in understanding a thing to be as it is.
Ad 3. A difference in form that comes solely from a distinct disposition of the matter produces no distinction in species, but only a numerical one. For distinct individuals have distinct forms, made distinct by their matter.°
Article 8. Does our intellect cognize the indivisible
prior to the divisible?
It seems that our intellect cognizes the indivisible prior to the divisible:
1. The Philosopher says in Physics I [184a10-12] that we understand and know by cognizing principles and elements. But indivisible things are the principles and elements of divisible things. Therefore indivisible things are known by us prior to divisible things.
2. We have a prior cognition of that which is included in the definition of a thing, because a definition comes from [terms] that are "prior and better known," as is said in Topics VI [141a26-b2]. But what is indivisible is included in the definition of what is divisible. For example, a line is a length without width whose ends are two points, as Euclid says. Also, the unit is included in the definition of number, since "number is a multitude measured by one," as is said in Metaphysics X [1057a3]. Therefore our intellect understands the indivisible prior to the divisible.
3. Like is cognized by like. But what is indivisible is more like the intellect than what is divisible is, since "the intellect is simple," as is said in De anima III [429b23]. Therefore our intellect has a prior cognition of the indivisible.
On the contrary. It is said in De anima III [430b20] that "what is indivisible is revealed as a privation." But a privation is cognized secondarily, and therefore so is the indivisible.
Reply. The object of our intellect, in its present state, is the quiddity of a material thing, which it abstracts from phantasms, as is clear from things said already [85.1]. And since that which is cognized first and per se by a cognitive power is its proper object, we can consider the order in which we understand the indivisible based on its relationship to such a quiddity.
Something is said to be indivisible in three ways, however, as is said in De anima III [430b6-26].
· In one way, as a continuum is indivisible: for it is actually undivided, but potentially divisible. We understand something indivisible in this way prior to its division into parts, because a confused cognition is prior to a distinct one, as was said [85.3cxx].
· In another way, something is said to be indivisible in species. The nature (ratio) of a human being, for example, is indivisible. Something indivisible in this way is also understood prior to its division into the parts of its nature, as was said above [85.3cxx], and also prior to the intellect's composing and dividing through affirmation or negation. And the reason for this is that the intellect in its own right understands this sort of two-part indivisible as its proper object.°
· In a third way, something is said to be indivisible that is entirely indivisible, like a point and a unit, which are neither actually nor potentially divided. This sort of indivisible is cognized secondarily, through privation of something divisible. (Thus a point is defined by privation: a point is what has no part; likewise the nature of one is to be indivisible, as is said in Metaphysics X [1052b16].) The reason it is cognized secondarily is that such an indivisible is opposed in a certain way to corporeal things, whose quiddity the intellect takes in first and per se. If our intellect were instead to understand through participation in separated indivisible substances, as the Platonists claimed, then it would follow that such an indivisible would be understood first. For the Platonists claimed that what is prior is what things have a prior participation in.
Ad 1. In acquiring knowledge, principles and elements are not always prior: for sometimes we go from sensible effects to the cognition of principles and intelligible causes. But when it comes to complete knowledge, the knowledge of effects always depends on cognizing principles and elements. For as the Philosopher says in that same passage [184a12-14], we believe ourselves to have knowledge when we can analyze composite things into their causes.
Ad 2. Point is not included in a generalized definition of line. For it is clear that in the case of an infinite line, and also in the case of a circle, there are points only potentially. But Euclid is defining a finite straight line, and so he includes point in his definition of line, as a limit in the definition of what is limited. The unit, however, is the measure of number, and so it is included in the definition of a measured number. But it is not included in the definition of the divisible, but rather conversely.
Ad 3. The likeness through which we understand is a species of the cognized thing in the one cognizing. Hence the cognition of a thing is prior not because of the likeness of the thing's nature to the cognitive capacity, but through the capacity's being well-suited to the object. If the former were the case then sight would cognize hearing more than it would color.°
Question 86. What Our Intellect Cognizes In Material Things
Next we must consider what our intellect cognizes in material things. Here there are four points of inquiry:
a1. Does it cognize singulars?
a2. Does it cognize the infinite?
a3. Does it cognize contingent things?
a4. Does it cognize the future?
Article 1. Does our intellect cognize singulars?
It seems that our intellect does cognize singulars:
1. Whoever cognizes a composition cognizes the terms of the composition. But our intellect cognizes this composition, Socrates is a human being, because it belongs to intellect to form a proposition. Therefore our intellect cognizes the singular that is Socrates.
2. Practical intellect directs action. But acts concern singulars. Therefore it has cognition of singulars.
3. Our intellect understands itself. But it is something singular ── otherwise it would not have any act, since acts belong to singulars. Therefore our intellect cognizes the singular.
4. Whatever a lower power can do a higher power can do. But the senses cognize singulars. Therefore, a fortiori, so does intellect.
On the contrary. The Philosopher says in Physics I [189a6-7] that "the universal is known by reason, the singular by sense."
Reply. In the case of material things, our intellect cannot directly and primarily cognize the singular. The reason for this is that the basis of singularity in material things is individual matter, whereas our intellect, as was said above [85.1], operates by abstracting an intelligible species from such matter. But that which is abstracted from individual matter is universal. Consequently our intellect is directly cognitive only of universals. Indirectly, however, and through a kind of reflection, as it were, it can cognize the singular. For as was said above [84.7], even after it has abstracted intelligible species, it cannot actually understand through them except by turning toward phantasms, in which it understands the intelligible species, as is said in De anima III [431b2]. In this way, then, it directly understands the universal itself through an intelligible species, whereas it indirectly understands the singulars that the phantasms concern. This is how it forms the proposition Socrates is a human being.
In this way the solution ad 1 is clear.
Ad 2. The choice of a particular course of action serves as the conclusion to a syllogism of practical intellect, as is said in Ethics VII [1147a24-31]. But something singular can be the direct conclusion of a universal proposition only on the mediating assumption of some singular proposition. So the universal reasoning of practical intellect produces movement only through the mediation of a particular apprehension belonging to the sensory part, as is said in De anima III [434a16-21].
Ad 3. The singular is incompatible with intelligibility not insofar as it is singular but insofar as it is material. For nothing is understood except immaterially. So if a singular is immaterial, as the intellect is, then it is not incompatible with intelligibility.
Ad 4. A higher power can do what a lower power can, but in a superior way. So that which the senses cognize materially and concretely, the intellect cognizes immaterially and abstractly. The former is to cognize the singular directly; the latter is to cognize the universal.
Article 2. Does our intellect cognize the infinite?
It seems that our intellect can cognize the infinite:
1. God exceeds everything infinite. But our intellect can cognize God, as was said above [Q12]. Therefore, a fortiori, it can cognize everything else that is infinite.
2. Our intellect is naturally suited to cognize genera and species. But some genera, such as number, proportion, and shape, have infinitely many species. Therefore our intellect can cognize the infinite.
3. If one body did not prevent another from existing in one and the same place, then nothing would stop infinitely many bodies from existing in one place. But one intelligible species does not stop another from existing at the same time in the same intellect, since it is possible to have a dispositional knowledge of many things at the same time. Therefore nothing stops our intellect from having a dispositional knowledge of the infinite.
4. The intellect, since it is not a power of corporeal matter, as was said [75.2], seems to be an infinite capacity. But an infinite power can range over the infinite. Therefore our intellect can cognize the infinite.
On the contrary. It is said in Physics I [187b7] that "the infinite, considered as infinite, is unknown."
Reply. Since a capacity is proportioned to its object, the intellect must be related to the infinite just as its object (the quiddity of a material thing) is related to the infinite. But in material things one does not find an actual infinity, only a potential infinity, inasmuch as one thing succeeds another (as is said in Physics III [206a18-23]). So in our intellect one finds a potential infinity with respect to taking up one thing after another. For our intellect never understands so much that it cannot understand more. But our intellect cannot actually or habitually cognize the infinite:
· Not actually, because our intellect can actually cognize at one time only that which it cognizes through a single species. But the infinite does not have a single species; otherwise it would have the character of being whole and complete. So it cannot be understood except by taking up part after part. (This is clear from its definition in Physics III [207a8]: for the infinite is "that which, if one takes a quantity of it, there is always something more to take.") Thus the infinite could not be actually cognized unless all of its parts were counted, which is impossible.
· For the same reason we cannot understand the infinite habitually. For an habitual cognition is caused within us by actually considering, for we are made to have knowledge by [first] understanding, as is said in Ethics II [1103a26-b26]. So we could not have dispositional knowledge of the infinite, distinctly cognized, unless we had already considered all of the infinite, counting them by a sequence of cognitions, which is impossible.
So our intellect can cognize the infinite neither actually nor habitually, but only potentially, as was said.
Ad 1. As was said above [1a 7.1], God is said to be infinite as a form that is not limited by any matter. In the case of material things, however, something is said to be infinite through the lack of formal limit. And because form is known in its own right, whereas matter without form is unknown, a material infinite is accordingly not known in its own right. But the formal infinite, God, is known in its own right, although unknown relative to us, because of a shortcoming in our intellect, which in its state of life at present is naturally suited to cognize material things. So at present we can cognize God only through his material effects. But in the future this shortcoming in our intellect will be removed by glory, and then we will be able to see God himself in his essence, although without comprehension.
Ad 2. Our intellect is naturally suited to cognize species through abstraction from phantasms. So those species of numbers and shapes that one has not imagined cannot be actually or habitually cognized, except perhaps generically and in their universal principles. This is a potential, confused cognition.
Ad 3. If two or more bodies were in a single place, they would not have to enter into that place successively so that the things located there would be numbered through their successive entrances. But intelligible species come into our intellect successively, since it does not actually think about more than one thing at the same time. So it must be that they are numbered, and that there are not infinitely many species in our intellect.
Ad 4. Our intellect cognizes the infinite to the extent it is infinite in power. For its power is infinite inasmuch as it is not limited by corporeal matter and is capable of cognizing the universal, which is abstracted from individual matter. It is consequently not limited to any individual but, considered of itself, extends to an infinite number of individuals.
Article 3. Does our intellect cognize contingent things?
It seems that the intellect is not cognitive of contingent things:
1. As is said in Ethics VI [1140b31-41a8], intellect, wisdom, and knowledge concern not contingent but necessary things.
2. As is said in Physics IV [221b29-30], things that exist at one time and not another are measured by time. But intellect abstracts from time, just as from other material conditions. Therefore since it is distinctive of contingent things that they exist at one time and not another, it seems that contingent things are not cognized by intellect.
On the contrary. All knowledge (scientia) is in intellect. But some branches of knowledge concern contingent things, like the moral sciences (which concern human acts, subject to free decision) and even the natural sciences (with regard to the portion that deals with generable and corruptible things). Therefore the intellect is cognitive of contingent things.
Reply. Contingent things can be considered in two ways: first, insofar as they are contingent; second, insofar as something necessary is found in them. For nothing is so contingent as to have within itself nothing that is necessary. The fact of Socrates' running, for instance, is of course contingent in itself, but the relationship of running to motion is necessary, since it is necessary that if Socrates runs, he moves. Now everything that is contingent is so with respect to its matter, because the contingent is what has the potential to exist and not to exist, and potentiality is associated with matter. Necessity, on the other hand, follows the character of the form, because things that follow from the form are necessarily present. Now it is matter that is the principle of individuation, whereas the universal nature is taken through abstracting the form from the particular matter. And it was said above [86.1cxx] that, per se and directly, the intellect concerns universals whereas the senses concern singulars. But singulars are, in a certain indirect way, the concern of intellect as well, as was said [86.1cxx]. So therefore contingent things, inasmuch as they are contingent, are cognized directly by sense and indirectly by intellect, whereas universal natures and the necessary aspects of contingent things are cognized by intellect. So if one focuses on the universal natures of the objects of knowledge, then all knowledge (scientiae) concerns necessary things. But if one focuses on the things themselves, then some knowledge concerns necessary things, whereas some concerns contingent things.
Through this, the solution to the objections is clear.
Article 4. Does our intellect cognize the future?
It seems that our intellect cognizes the future:
1. Our intellect cognizes through intelligible species, which abstract from here and now and thus stand indifferent to all times. But it can cognize the present. Therefore it can cognize the future.
2. A human being, when deprived of the senses, can cognize some things in the future, as is clear in those asleep and in the frenetic. But when deprived of the senses, one's intellect becomes stronger. Therefore the intellect, considered in its own right, is cognitive of the future.
3. The intellective cognition of a human being is stronger than any sort of cognition belonging to brute animals. But there are some animals that cognize some things in the future ── when crows repeatedly caw, for instance, they signify that rain is soon to come. Therefore a fortiori the human intellect can cognize the future.
On the contrary. Ecclesiastes 8.6-7 speaks of the great affliction of human beings: they are ignorant of things past and can through no messenger know the future.
Reply. The same sort of distinction should be made for the cognition of future things as for the cognition of contingent things. For the things themselves in the future, as they are contained within time, are singulars, and the human intellect can cognize these only through reflection, as was said above [86.1cxx]. But the natures (rationes) of future things can be universal and perceptible by intellect, and there can also be knowledge (scientiae) of these.
But in order to speak generally about the cognition of the future, we should know that things in the future can be cognized in two ways, in themselves and in their causes:
· Only God can cognize future things in themselves. They are present to God even while in the course of events they are future, inasmuch as his eternal intuition is cast all at once over the whole course of time. (This was said above when God's knowledge was discussed [1a 14.13].)
· We too can cognize things in the future, considered in their causes. And if they are in their causes in such a way as to come necessarily from these causes, then they are cognized with the certainty of knowledge ── just as an astronomer forecasts a future eclipse. If, on the other hand, they are in their causes in such a way as to come from these for the most part, then they can thus be cognized by a conjecture that will be more or less certain depending on whether the causes are more or less inclined toward their effects.
Ad 1. That argument holds for the cognition that comes through the universal natures of the causes. Through these natures, the future can be cognized in keeping with how the effect is ordered to its cause.
Ad 2. As Augustine says in De Genesi ad litteram XII [xiii.27], the soul has a kind of power for prophecy, so that it can by its nature cognize the future. So when it withdraws from the bodily senses and turns back somehow toward itself, it comes to participate in knowledge of the future. This view would be reasonable if we were to hold that the soul takes its cognition of things by participating in the Ideas, as the Platonists claimed. For then by its nature the soul would cognize the universal causes of all effects, but for its being impeded by the body. Hence when it is turned away from the bodily senses, it cognizes the future. But because this mode of cognizing is not natural to our intellect ── instead, it naturally takes its cognition from the senses ── it is thus not on account of the soul's nature that it cognizes the future when deprived of the senses. This instead occurs through an impression from certain higher causes, spiritual and bodily.
· The impression is spiritual when, by divine power, through the ministry of angels, the human intellect is illuminated and its phantasms are arranged so as to cognize various things in the future. Alternatively, this occurs through the operation of demons, when one's phantasia is agitated so that one comes to presage various things in the future that the demons cognize (as was said above [1a 57.3]). The human soul is better suited to receive such impressions from spiritual causes when it is deprived of the senses, because through this deprivation it moves closer to the spiritual substances and becomes freer from external disturbances.
· The cognition of the future also occurs through an impression from higher bodily causes. For it is clear that higher bodies make an impression on lower bodies. So since the sensory powers are actualities of bodily organs, it follows that phantasia is in some way affected by an impression from the heavenly bodies. So since the heavenly bodies are the cause of many things in the future, the imagination acquires the signs of various things in the future. But these signs are perceived more at night and by those asleep than during the day and by those awake. For as is said in the De somno [464a12-19],
Things conveyed during the day are more dislocated, because the night air is less agitated given that nights are quieter. They also, because of sleep, produce sensations within the body, because slight internal movements are sensed more by those asleep than by those awake. These motions produce the phantasms through which those asleep foresee future things.
Ad 3. Brute animals have nothing above phantasia that arranges their phantasms ── in the way that human beings have reason ── and so the phantasia of brute animals entirely follows the heavenly impression. So various things in the future (rain and the like) can be cognized from the movements of such animals more than from the movements of human beings, who are moved by the counsel of reason. Thus the Philosopher says in the De somno [464a22-25] that some of the most imprudent have the most foresight, "because their intelligence is not affected by care but is led, deserted and emptied of all things, moved by what moves it."
 QDV 10.1.
 Homiliae in evangelia 29.2 (PL 76, 1214b). Cf. 84.3 obj. 1.
 75.2cxx, 75.5cxx, 84.2cxx.
 1a 14.4, 54.2.
 80.1 ad 2.
 De anima III 9, 432b5; see 87.4cxx.
 1a 19.1c, 59.1c.
 QDV 16.1 ad 13; InDA III.7.75-90, III.9; III Sent. 220.127.116.11.
 79.1 ad 4.
 77.3cxx, with note.
 1a 58.1c, 58.3c.
 1a 58.1.
 Themistius, De anima III.5 (105.13 - 109.3); see Averroes, De anima III.20 (p. 446).
 Averroes, De anima III.20 (p. 449). See 78.4cxx.
 De an. III 4, 429a22.
 ST 1a 54.4; SCG II.77; QDSC 9; CT 83, 87-88; QDA 4; InDA III.10.
 This and the next argument appear in William of Auvergne, Tractatus de anima VII.4 (207ab).
 84.1cxx, 84.4cxx.
 77.3cxx, with note.
 ST 1a 84.4c, 88.1c; II Sent. 17.2.1, 28.1.5; SCG II.76, 78; QDSC 10; QDA 5; QDV 10.6; CT 86; InDA III.10; De unitate.
 William of Auvergne, Tractatus de anima VII.3 (206a), VII.4 (208ab).
 76.1 ad 1, with note.
 III.5 (103.34-36). See Plato, Republic VI (508b-9b), and Aristotle, De anima III 5, 430a14-17.
 Aristotle, De an. III 5, 430a15.
 See parallel passages for 79.4.
 Avicenna, Metaphysics I.5.
 Alexander of Aphrodisias, De intellectu; Avicenna, Liber de anima V.5, pp. 126-27 (see 79.6cxx, 84.4cxx); Averroes, De anima III.18-19 (see 88.1cxx).
 De an. III 5, 430a18-19.
 76.1 ad 1.
 ST 1a2ae 67.2; I Sent. 3.4.1; III Sent. 26.1.5 ad 4; IV Sent. 18.104.22.168 ad 4 (= ST 3a supp. 70.2 ad 4), 50.1.2; SCG II.74; QDV 10.2, 19.1; QQ 3.9.1, 12.9.1; In1C 13.3; InDMR 2.
 Avicenna, Liber de anima V.6 (pp. 147-48).
 Liber de anima V.6 (pp. 147-48). Cf. obj. 3.
 Liber de anima V.6 (pp.148-49). Cf. 84.4cxxx.
 Liber de anima V.6 (pp. 149-50).
 QDV 10.3; ST 1a 93.7 ad 3; I Sent. 3.4.1; SCG II.74.
 De trinitate X.xi.18.
 De an. III 5, 430a14-15.
 Peter Lombard, Sent. I.iii.2.
 79.6 ad 3.
 QDV 15.1; III Sent. 22.214.171.124; ST 1a 83.4c; InDDN 7.2 '713.
 QDV 15.2; ST 1a2ae 74.9; II Sent. 24.2.2.
 De trinitate XII.vii.12.
 De fide orthodoxa II.22.
 De trinitate XII.vii.12.
 De trinitate XII.xiv.22.
 79.11 ad 2, with note.
 78.1cxx, 79.7cxx.
 Avicenna, Liber de anima V.1 (p. 79).
 InDA I.8; SCG III.42.
 De fide orthodoxa II.22.
 E.g., Avicenna, Metaphysics X.1 (p. 522).
 1a 58.1.
 E.g., Pseudo-Dionysius, Celestial Hierarchy ch. 2.
 E.g., Alexander of Aphrodisias, De intellectu, 106-7 (cf. Summa contra gentiles III.42); Avicenna, Liber de anima I.5 (p. 94-100); Anonymous, "The Soul and its Powers," p. 0000000.
 79.6 ad 3.
 1a 14.7, 79.2cxx.
 QDV 3.3; InNE VI.2; InDA I.1.56-62, III.15; InPA I.41.136-45 ('362); III Sent. 126.96.36.199.
 QDV Q16; II Sent. 24.2.3.
 81.1 obj. 2 & ad 2, with note.
 Commentaria in Ezechielem I.1.7 (PL 25, 22ab) ── cf. Glossa ordinaria, vol. 3 p. 224a.
 Sensual appetite; see 81.1.
 Met. IX 2, 1046b4-5; see 82.1 obj. 2.
 William of Auxerre, Summa aurea II.12.
 Followers of Alexander of Hales, Summa theologica II.1.418 (vol. 2, p. 493).
 79.9cxx, with note.
 QDV Q17; II Sent. 24.2.4.
 In Romanos II.9 (PG 14, 893B).
 Commentaria in Ezechielem I 1.7 (PL 25, 22c) ── cf. Glossa ordin. (IV, 210 F).
 Homily 12 (PG 31, 405C).
 De fide orthodoxa IV.22.
 ST 1a 76.2 ad 3; QDV 10.4; SCG II.75; De unitate 5; InDA III.8; QDSC 9 ad 6.
 Aristotle, De an. I 2, 404b16-18.
 ST 1a 14.1; InDA III.7; II Sent. 3.3.1; III Sent. 14.1.2; SCG II.98; QDV 8.8.
 Celestial Hierarchy 12.2.
 Aristotle, De an. I 2, 404b8-11.
 Aristotle ascribes these theories, in turn, to Democritus (De an. I 2, 405a5-13), Diogenes of Apollonia (ibid., 405a21-25), and Hippo (ibid., 405b1-5).
 Aristotle, De gen. et cor. I 1, 314a15-17; De an. I 2, 404b11-15.
 Aristotle, De an. III 3, 427a17-21. See 84.6cxx.
 1a 55.1-2.
 ST 1a 55.2, 89.1c, 117.1, 1a2ae 51.1; SCG II.83; QDV 10.6, 11.1, 18.7, 19.1c; QDA 15; QQ 3.9.1c. For the parallel case of innate virtues, see ST 1a2ae 63.1, QDVCom 8, III Sent. 188.8.131.52.
 Homiliae in evangelia 29.2 (PL 76, 1214B).
 De anima III 4, 430b30-31.
 84.4cxx, 89.1cxx, with note.
 Aristotle, Post. an. I 18, 81a38-39.
 ST 1a 65.4, 79.4, 79.6; QDA 15; QDV 10.6, 11.1; SCG II.74.
 Aristotle, De anima III 4, 430a4. See 80.1cxx.
 Avicenna, Liber de anima V.5 (p. 126).
 Aristotle, Post. an. I 18, 81a38-39.
 Metaphysics VII 14-16.
 Liber de anima V.6 (pp. 146-48); Metaphysics VII.2 (pp. 358-60).
 Avicenna, Metaphysics IX.4; Liber de anima V.5 (pp. 126-28), V.6 (pp. 143-44).
 Liber de anima V.6 (pp. 146-150). See 79.6cxx.
 84.3cxxx, 89.1cxxx, Avicenna, Liber de anima V.5 (pp. 131-32).
 Liber de anima V.5 (pp. 127-28).
 Divine Names 7.2.
 79.4cxx, 84.5cxx.
 ST 1a 12.11 ad 3, 88.3, 1a2ae 109.1; QDV 10.6 ad 6, 11.1c; SCG III.47; QQ 3.9.1c, 10.4.1; CT 129; InDT 1.1; II Sent. 28.1.5.
 84.1cxx, 84.4cxx.
 QDV 10.6, 19.1; QDA 15; QQ 8.2.1; CT 81-83.
 75.3cxx, 84.2cxx.
 De an. III 3, 427b6-14.
 De somno 1, 454a7-11.
 De an. I 1, 403a5-10.
 De an. III 4, 429a18-27.
 De an. III 5, 430a18-19.
 84.2 ad 1.
 De an. I 1, 403a8-10.
 ST 1a 12.4c, 85.1c, 89.1; SCG II.73, II.80-81; QDV 10.2 ad 7; InDMR 2-3; QDA 15; InDA III.13; In1C 13.3; II Sent. 20.2.2 ad 3; III Sent. 31.2.4.
 79.8 ad 3.
 75.3, 77.5.
 1a QQ56-57.
 Romans 1.20 (see, e.g., 79.9cxx).
 Divine Names 1.5-8.
 ST 1a 12.12, 101.2, 2a2ae 154.5, 3a 11.1 ad 3; QDV 12.3 ad 1-3, 28.3 ad 6.
 Aristotle, De somniis 2, 460b16-18.
 ST 1a 12.4, 13.12 ad 3; SCG II.77; InMet II.1; InDA II.12, III.8, III.12.
 79.3 ad 2.
 1a 57.1.
 Obj. 1. The objection, and the following reply, closely follow Boethius's Second Commentary On Porphyry's Isagoge, I.10-11 (tr. Spade, pp. 23-24).
 78.3 ad 2xx.
 78.4 ad 5.
 ST 1a 14.5 ad 3; SCG II.75; QDV 10.9; QDSC 9 ad 6; CT 85; De unitate 5; InDA III.8.264-79; I Sent. 35.1.2.
 De anima III 4, 430a4. See 80.1cxx, 84.4 obj. 1, 87.1 obj. 3 & ad 3.
 Aristotle ascribes this view to various Presocratics (De an. III 2, 426a20-21; Met. IV 5, 1009b1-38; Met. IX 3, 1047a4-6).
 Aristotle, Met. IV 5, 1009b1-38; De an. I 2, 404a27-28.
 De an. III 8, 431b29.
 Aristotle, Met. IV 7, 1012a25.
 InPhys I.1; InPA I.4; SCG II.98; ST 1a 108.3c; InDT 1.3c.
 Aristotle, Physics I 1, 184a18.
 Aristotle, Categories 12, 14a29-30.
 77.1 ad 1.
 ST 1a 12.10; 58.2; SCG I.55; QDV 8.14; QDA 18 ad 5; QQ 7.1.2; II Sent. 3.3.4; III Sent. 14.2.4.
 Liber de causis, Proposition 2.
 ST 1a 58.4; InDA III.11; SCG I.55, I.58.
 85.4 ad 4.
 86.1cxx, 86.3c.
 75.5cxx, 79.6cxx.
 84.7cxx, 85.1cxx.
 85.1 ad 2, 85.3 ad 4.
 ST 1a 17.2-3, 58.5; QDV 1.11-12; SCG I.59, III.108; InPH I.3; InDA III.11; InMet VI.4, IX.11; I Sent. 19.5.1 ad 7.
 75.5cxx, 85.1 ad 1.
 ST 1a 12.6 ad 2, 1a2ae 63.1; IV Sent. 49.2.4 ad 1; QDV 2.2 ad 11; InDA II.19.85-114.
 Obj. 1; see 85.6sc.
 76.5cend, with note.
 ST 1a 11.2 ad 4; InDA III.11.
 Elements I, definitions 2-3.
 Euclid, Elements I, definition 1.
 84.4cxx, 84.5cxx, 84.6cxx.
 QDV 2.5-6, 10.5; QDA 20; QQ 7.1.3, 12.8; II Sent. 3.3.3; IV Sent. 50.1.3; SCG I.65; InDA III.8.
 ST 1a 14.12; QDV 2.9; CT 133.
 75.5 obj. 4 & ad 4, 76.5 ad 4.
 1a 7.2-4.
 75.5c&2, 84.2cpenult.
 QDV 15.2 ad 3; InNE VI.1; CT 133.
 84.1 ad 3.
 ST 1a 57.3, 2a2ae 95.1, 172.1; SCG III.154; QDV 8.12; QDM 16.7; CT 134; I Sent. 38.5 ad 2; II Sent. 7.2.2.