Thomas Aquinas -- Commentary on Aristotle's De memoria et reminiscencia

Translated by Robert Pasnau

Chapter 2 (449b30-450a25)
1-7. After the Philosopher has shown what memory is, he here shows what part of the soul it pertains to. And in this connection he does two things. First he sets out something that is necessary to make the thesis clear. Second he makes the thesis clear (beginning at Magnitudinem et motum, etc.).

7-12. In connection with the first he does three things. First he puts forth his plan. Second he makes what he has said clear, through an example (beginning at Accidit enim eadem passio, etc.). Third he shows what in this connection has to be made clear elsewhere (beginning at Propter quam igitur causam, etc.).

His plan
13-17. So he first sets out that in the book De anima he has said regarding phantasia what it is: namely, that it is a movement made by actualized sense. He also said, in the same book, that it is not possible for a human being to understand without a phantasm.

18-47. Next, when he says Accidit enim, etc., he makes clear what he had last said. For it could seem unacceptable to someone that a human being cannot understand without a phantasm. For a phantasm is a likeness of a corporeal thing, whereas understanding is of universals that are abstracted from particulars. And so to make this clear he invokes a certain example, saying that it occurs with regard to intellect, as regards its needing phantasms, just as it occurs when one sketches geometrical shapes. In such cases one does indeed sketch a triangle of one determinate quantity, but still the geometer in his demonstration doesn't use any determinate quantity of the triangle. And likewise in the case of a human being who wants to understand some thing: a phantasm of some determinate quantity -- being of a singular thing -- is put before his eyes. For instance: someone who wants to understand a human being has occur to him an imagination (imaginatio) of some two-cubit human being; but intellect understands the human being insofar as he is a human being, not insofar as he has this quantity. But because intellect can understand the nature of quantity, he thus adds that, if certain things that ought to be understood are quantities by their nature -- e.g., line, surface, number -- but still are not finite -- i.e., a determinate determination of singularity -- all the same still a phantasm of a determinate quantity is placed before one's eyes. In this way when someone wants to understand a line, there occurs to him the phantasm of a two-foot line. But intellect understands it only with respect to the nature of quantity, not in respect of its being two-feet-long.

48-52. Next, when he says Propter quam igitur causam, etc., he shows what is reserved for other consideration. And he says that it pertains to another account to assign the cause of why a human being can understand nothing without succession (continuo) and time.

53-69. This is so insofar as a human being can understand nothing without a phantasm. For a phantasm must occur with succession and time, because it is a likeness of a singular thing that is here and now. But as for why a human being cannot understand without a phantasm, the reason can easily be given with respect to the first reception of intelligible species that are abstracted from phantasms, according to Aristotle's teaching in De anima III. But it is clear to experience that even one who has already acquired intelligible knowledge through intellectively cognized species cannot actually consider that of which he has knowledge unless some phantasm occurs to him. This is why when the organ of imagination is harmed a human being is impeded not only from understanding something anew, but also from considering things that he has understood already: as is clear in the case of frenetics.

70-85. But someone could say to this that intelligible species do not remain in the human possible intellect except as long as one actually understands, whereas after one stops actually understanding, intelligible species cease to be in intellect: in just the way that a light ceases to be in air at the absence of the illuminating body. And thus it is necessary, if the intellect wishes to understand anew, that it should again turn itself toward phantasms so as to acquire intelligible species. But this view is expressly contrary to the words of Aristotle in De anima III, where he says that, when possible intellect is made singular intelligible things [429b5-6], which happens through their species, then it is also in potentiality for actual understanding. This view is also incompatible with reason, because intelligible species are received in the possible intellect unmoveably -- in keeping with its [intellect's] mode.

86-103. But possible intellect's having intelligible species even when it does not actually understand is not quite the same as in the sensory powers, where, on account of the condition of the corporeal organ, it is one thing to receive the impression (this brings about actual sensing) and another to retain it, even when the thing is not actually sensed (as Avicenna objects). Rather [this characteristic of intellect] occurs because of the different levels of being of intelligible forms: either in respect of pure potentiality (before one discovers or learns), or in respect of pure act (when one actually understands), or in an intermediary manner between potentiality and actuality (this is to be disposed). Therefore the possible human intellect needs a phantasm not only in order to acquire intelligible species, but also to inspect (inspicit) them [i.e., the species] in some way in phantasms. And this is what De anima III says: "So one understands the species of intellective things in phantasms."

104-113. Yet the reason for this is that an operation is proportionate to its power and essence, whereas the intellective capacity of a human being is in the sensory capacity, as is said in De anima II [cf. InDA II.6.64-74]. And thus its proper operation is to understand intelligible things in phantasms, just as the operation of a separate substance's intellect is to understand things understood in their own right. And thus the cause of this has to be assigned to metaphysics, to which it pertains to consider the different levels of intellect.

114-118. Next, when he says Magnitudinem autem et motum, etc., he shows the part of the soul to which memory pertains. And first he does so through an argument, second through indications (beginning at Unde et alteris, etc.). Third he concludes his thesis (beginning at Cuius quidem igitur, etc.)

119-165. So he says first that it is necessary that magnitude and movement are cognized by the same part of the soul by which time is cognized as well. For these three follow from one another both in division and in what it is to be finite and infinite, as Physics VI proves. But magnitude is cognized by sense, since it is one of the common sense objects. And likewise movement too, especially local movement, is cognized insofar as the distance of magnitude is cognized. Time, however, is cognized insofar as prior and posterior in movement are cognized. Hence these three things can be perceived by sense. But something is perceived by sense in either of two ways. One way is through the alteration itself of sense by sense object: in this way proper and common sense objects are cognized by the proper senses and the common sense. In a second way something is cognized by a kind of secondary movement that is left over from the first alteration of sense by sense object. This movement remains even sometimes after the sense objects are gone, and it pertains to phantasia, as the De anima shows. The phantasm that appears through a secondary alteration of this sort is a passion of the common sense, because it follows from the whole alteration of sense, which begins at the proper senses and is terminated at the common sense. Hence it is clear that the three things in question (magnitude, movement, and time), inasmuch as they are comprehended in a phantasm, are cognized through the common sense. But memory, not only of sensible things (for instance, when someone remembers his having sensed) but also of intelligible things (for instance, when someone remembers his having understood) is not without phantasms. For sensible things, after they go away, are not perceived by sense if they are not in a phantasm, while understanding does not occur without a phantasm, as was asserted above. Hence Aristotle concludes that memory belongs to the soul's intellective part per accidens, but per se belongs to the first sensory capacity (primi sensitivi) -- that is, to the common sense. For it was said above that "a determinate quantity" is proposed to intellect in a phantasm, although intellect in its own right considers a thing absolutely. To memory, on the other hand, there pertains the apprehension of time according to a kind of determination -- namely, according to the distance in the past from this present now. Hence memory pertains per se to the apparition of a phantasm, while per accidens it pertains to the judgement of intellect.

166-194. It could seem to someone, however, based on what has been said, that imagination and memory are not powers distinct from common sense, but are certain states (passiones) of it. Avicenna, however, reasonably showed that they are different powers. For because the sensory powers are actualities of corporeal organs, it is necessary for there to be different powers for the reception of sensible forms, which pertains to sense, and the conservation of them, which pertains to phantasia or imagination. In this way we see in the case of physical things that reception and conservation pertain to different principles. For humid things receive well, whereas dry and hard things conserve well. Likewise too it pertains to different principles to receive or to conserve (a) a form received through the sense and (b) some intention not apprehended through sense, which the estimative power perceives even in other [nonhuman] animals, whereas the memory power retains it. This latter power remembers a thing not absolutely, but as it has in the past been apprehended by sense or intellect. Yet it may be that of various powers one is as it were the root and origin of the others, and that their acts presuppose the act of that first power: in the way that the nutritive power is as it were the root of the growing and generative powers, both of which use nutrition. Likewise, then, the common sense is the root of phantasia and memory, which presuppose the act of common sense.

195-215. Next, when he says Unde et alteris, etc., he makes what he had said clear through two indications. The first of these is taken from the standpoint of animals having memory. He says that, because memory belongs per se to the first sensory capacity, memory as a result is in certain other animals having sense and lacking intellect, and not only in human beings and certain others having opinion, which could also pertain to the speculative intellect, and prudence, which pertains to the practical intellect. But if memory were one of the intellective powers, then it would not be in many of the others animals, for whom it is manifestly clear that they have memory and yet do not have intellect, and so perhaps memory would not be in any of mortal things except human beings, because only human beings among mortals have intellect. (He says "perhaps" on account of certain people who questioned whether certain animals other than humans might have intellect, because of a number of activities like the activities of reason - - like the activities of primates and of certain animals of this sort.)

216-233. He introduces a second indication beginning at Quoniam neque nunc, etc., which is taken from animals not having memory. And he says that it is clear from this that memory pertains per se to the sensory part, because even now when we suppose that only human beings among mortals have intellect, memory is not in all animals but only those have it that sense time. For some animals perceive nothing save at the presence of sense objects, such as certain immobile animals, which on this account have an indeterminate imagination, as De anima III says. And on this account they cannot have cognition of prior and posterior, and consequently nor time. Hence they do not have memory. For always, when soul acts through memory, as was said earlier, soul senses at one and the same time that it has seen or heard or learned this before. Yet prior and posterior pertain to time.

234-241. Next, when he says Cuius quidem igitur, etc., he concludes the thesis. And he says that it is clear from the aforesaid to which part of the soul memory pertains -- for it pertains to that to which phantasia pertains -- and that those are memorable per se of which there is phantasia -- namely, sensible things. Per accidens, however, things that are memorable are intelligible, and they are not apprehended by human beings without phantasia.

242-248. And thus it is that things that have a subtle and spiritual consideration can less be remembered, whereas things are more memorable that are gross and sensible. And it must be, if we wish to remember easily any intelligible reasons, that we bind them, as it were, by certain other phantasms -- as Cicero teaches in his Rhetoric.

249-252. Yet memory is placed by some in the intellective part, inasmuch as every habitual conservation of things that pertain to the intellective part is understood through memory.

Chapter 3 (450a25-451a17)
1-5. Dubitabit autem utique aliquis, etc. Now that the Philospher has revealed what memory is and what part of the soul it belongs to, he here reveals the cause of remembering. And in this connection he does two things. First he puts forward a puzzle; second he resolves it (beginning at Aut est ut contingit, etc.).

6-10. In connection with the first he does three things. First he raises the puzzle. Second he makes clear something that the puzzle presupposed (beginning at Manifestum enim quoniam oportet, etc.). Third he brings out arguments regarding the question (beginning at Set si quidem tale est, etc.).

11-16. He says first, then, that since some kind of affection has an affect on the soul, in remembering, as if it were present, while the thing which we remember is absent, one could be puzzled about why we remember that which is not present -- namely, the thing -- and we do not remember the affection that is present.

17-21. Next, when he says Manifestum enim, etc., he makes clear something that he had presupposed, namely that some kind of affection is in the soul when we remember. And he makes this clear first through its cause, secondly through indications (beginning at Unde et hiis quidem, etc.).

22-35. So he says first that it is clear that one must understand that some such affection from sense is made in the soul and in the organ of the living body. We say that the memory of this soul is as if a kind of disposition. This affection, indeed, is as if a kind of picture, because the sense object impresses its likeness on the sense, and this sort of likeness remains in imagination even once the sense object has gone. And thus Aristotle adds that the movement that is produced by the sense object on the sense impresses on imagination as if a kind of sensible shape, which remains when the sense obect is gone. This happens in the way in which those who make a seal with a signant ring impress some kind of shape in the wax, which remains even when the seal or ring is removed.

35-44. Yet he says "in the soul and in part of the body" because, since this sort of affection pertains to the sensory part, which is the act of a physical organ, this sort of affection pertains not only to soul, but to the compound. Also, he calls memory a "disposition" of this part because memory is in the sensory part, and because sometimes we do not actually apprehend the things we preserve in memory, but hold onto them dispositionally, as it were.

45-79. Next, when he says Unde et hiis quidem, etc., he makes the matter clear through indications, namely that in remembering the affection mentioned above is present. He says that, because such an affection is necessary for memory, it happens that for some memory is not produced because they are in great movement, whether this happens on account of affection (either of the body, as happens in the sick and drunk, or of the soul, as in the case of those who are stirred to anger or concupiscence), or this may also occur on account of age (considering growth or decline). And so on account of these sorts of causes the human body is in a kind of flux, and thus cannot retain the impression that is brought about by the movement of the sensible thing. This is what would happen if some movement or even seal were impressed on flowing water; for immediately, because of that flux, the shape would be lost. But in certain others the impression just mentioned is not received: sometimes, indeed, on account of the humors being frozen by the cold. In this way it happens to those who find themselves in great fear that because of a kind of frigidity something cannot be impressed on their soul. And Aristotle gives the example of ancient buildings. When a wall is new, before the cement is thickened, it can easily be altered, whereas it cannot after it is aged. At other times, then, this happens not because of frigidity, but because of the natural hardness of that which should receive the affection. For earthen bodies have a hardness even if they are hot, whereas watery bodies are made hard by being made very cool. And on account of the causes just given, those who are very young (children, that is) and also the old are non- remembering, because the bodies of children are in flux on account of growth, whereas the old on account of decline. Hence an impression is not well retained in either.

80-89. Yet it happens that things that someone takes in from childhood he holds in memory more firmly. This happens because of the vehemence of the movement by which it happens that things which we wonder at are more impressed on memory. Yet we chiefly wonder at things that are new and unusual, whereas to children newly come into the world wonder comes more greatly with respect to things that seem unusual. This is the cause of their being firmly remembered. But with respect to the condition of a body in flux, they are naturally suited to be transient in memory.

90-99. Aristotle adds, however, that likewise with respect to the aforesaid neither seem to be good at remembering: neither those who are quite quick at apprehension, nor those who are quite slow. For those who are quite quick are more wet than they need be (for it is easy for wet things to receive an impression), whereas those who are more slow are also harder. And so, regarding the quick, the phantasm's impression does not remain in the soul, whereas it does not touch those who are hard -- i.e., they do not receive the phantasm's impression.

100-112. Yet what was said can be spelled out in another way, so that first he is understood to have assigned, on acccount of supervening movement, the reason for the defect in memory, and then afterwards he made clear through the example of young and old. Second, however, he assigned a cause on the basis of natural constitution: either because in some a watery humor is abundant that is cold and wet, and thus in them the impressions of phantasms are easily scattered -- just as ancient buildings easily decay; or because an earthen humor is abundant in some, who because of hardness do not receive an impression. This he later made clear through the example of the quick and slow.

113-118. It is important to consider, however, that Aristotle supposed the phantasm's impression to be made "in the soul and in part of the body" so that afterwards he would show that human beings are related differently to this sort of impression on account of a differing bodily disposition.

119-127. Next, when he says Set si quidem tale, etc., he treats the question proposed earlier. And first, as if what had been supposed had already been made clear, he resumes with the question. He says that if this happens in connection with memory, namely that some kind of affection is present in it like a picture, then it is important to ask whether someone remembers this affection that exists as present in memory, or the sensible thing by which this impression has been made.

128-132. Second (beginning at Si quidem enim hoc, etc.) he objects to one side. And he says that, if someone were to say that a human being remembers this present affection, then it would follow that we would remember nothing absent, which runs against the things determined above.

133-142. Third (beginning at Si vero illud, etc.) he objects to the other side, as if through three arguments. He introduces the first of these by saying that if someone remembers the thing by which the affection has been made, then it seems unacceptable that a human being would sense that which is present -- viz., the affection -- and that at the very same time as this he would remember that which is absent, which cannot be sensed. For it was said that memory pertains to the primum sensitivum [ch.2, 450a14]. Thus it does not seem that sense is of one, memory of the other.

143-156. He introduces the second beginning at Et si est simile, etc. And he says that, if an affection of this sort that is present to the one remembering is in us like a kind of shape or picture of sense itself -- i.e., is representing the first alteration of sense by sense object -- then why will memory be of something else, namely the object (res) and not the very shape or picture itself? For when there is a shape of sense, it is clear that it can be apprehended. And this is clear by experience. For he who remembers considers (speculatur) something through intellect with respect to this affection or senses through the sensory part. But it seems unacceptable that, when that which falls under apprehension is present, it is not apprehended but rather something else is.

157-164. He introduces the third argument beginning at Quomodo igitur, etc. And he asks how someone could remember through interior sense that which is not present. For since the exterior sense is conformed to the interior, it should follow that even the exterior sense is of a non-present object, in such a way, in fact, that it would be possible to see and hear a non-present object. This seems unacceptable.

165-170. Next, when Aristotle says Aut est ut contingit, etc., he resolves the puzzle set forward. And first he shows the cause of why remembering occurs. Second he shows the cause of something's being well preserved in memory (beginning at Meditationes autem, etc.). Third he gives an overview (beginning at Quid quidem igitur, etc.).

171-173. In connection with the first he does two things. First he resolves the puzzle. Second he makes the solution clear through an indication (beginning at Et ob hoc aliquando, etc.).

174-192. So he says first that one can account for why the thing stated -- viz., that someone senses a present affection and remembers something absent -- occurs and is the case. And he offers the example of an animal that is depicted on a slate, which is indeed both a depicted animal and an image of a true animal. And, since that to which both of these apply is the same in subject, nevertheless the two differ in definition (ratione). Thus the consideration of it insofar as it is a depicted animal is different from that insofar as it is the image of a true animal. So too, the phantasm that is in us can be taken either as it is something in itself, or as it is the phantasm of another. And, on one hand, in its own right it is a kind of speculative object (speculamen) -- that which intellect considers speculatively -- or a phantasm, as far as it pertains to the sensory part. On the other hand, inasmuch as it is the phantasm of another that we have already sensed or understood, thus it is considered as an image leading to another, and as the principle of remembering.

192-214. And so, when soul remembers in virtue of the movement of a phantasm, if soul is turned toward it in its own right, it thus seems that either something intelligible is present to soul, that intellect looks toward a phantasm, or simply the phantasm is present, which the imaginative power apprehends. Yet if soul would turn toward a phantasm insofar as it is the phantasm of another, and would consider it as an image of that which it has already sensed or understood (as stated regarding a picture), then just as he who does not see Coriscus considers a phantasm of him as the image of Coriscus, this {or: here} is already a different affection belonging to this consideration, because, namely, this already pertains to memory. And just as it happens with the phantasm of some singular person -- e.g., Coriscus -- that sometimes he is considered in his own right, and sometimes as an image, so also does this happen with regard to intelligible things. For when intellect looks to a phantasm as to a kind of depicted animal, if it looks to it in its own right, then in this way only some sort of intelligible is considered. But if intellect looks to it insofar as it is an image, then in that way it will be the principle of remembering, as occurs there -- i.e., in connection with particulars.

215-226. In this way, therefore, it is clear that when the soul turns toward a phantasm as it is a kind of form preserved in the sensory part, then thus it is an act of imagination or phantasia, or else of intellect considering in regard to a certain universal (circa hoc universale). But if the soul turns toward it insofar as it is the image of what it has already seen or understood, then this pertains to the act of remembering. And because to be an image signifies a kind of intention in regard to a particular form (circa hanc formam), thus Avicenna appropriately says that memory involves intention, while imagination involves a form apprehended through sense.

227-257. Next, when Aristotle says Et ob hoc aliquando nescimus, etc., he makes what he had said clear through a number of signs. And he says that, because we remember when we attend to a phantasm insofar as it is an image of what we have already sensed and understood, thus men are related to an act of memory in three ways. For sometimes, although we have in ourselves the movements of phantasms that have been made by that which we have already sensed, which, that is, are left by the first alteration of sense by sense object, nevertheless we do not know whether it is the case that this movement is in us in virtue of our having already sensed something; thus we are in doubt over whether we remember or not. Second, it sometimes happens that a human being understands and remembers that he has already heard or seen something, the phantasm of which now comes before us. This strictly is remembering, and this happens when one who speculatively considers a phantasm is indeed moved by that present phantasm, but considers it inasmuch as it is the image of another which he had already sensed or understood. In a third way, however, sometimes the contrary of the first way occurs -- in such a way, that is, that a person believes himself to remember and still does not remember. This occured to someone who was called Antipheron, who came from Orites; and likewise it happens to others who suffer from mental confusion. For they assess phantasms that newly come into them as if they were of things already done, as if they remember things that they never saw or heard. And this happens when someone considers that which is not the image of a different thing done before as if it were the image of that thing.

258-270. Next, when he says Meditationes autem, etc., he shows what memory is preserved through. And he says that the frequent meditations over things we have sensed or understood preserve memory so that someone remembers well the things he saw or understood. But to meditate is nothing other than to consider things over and over as an image of things already apprehended, and not only [to consider them] in their own right. This manner of considering pertains to the nature (ratio) of memory. Yet it is clear that by the frequent act of remembering the disposition of memorable things is confirmed, just as is any disposition through similar acts; and when the cause is multiplied, the effect is strengthened.

271-281. Next, when Aristotle says Quid quidem igitur est, etc., he gives an overview of the things said above. He says that it has been stated what memory and remembering are, because memory is a disposition -- i.e., a certain dispositional preservation -- of a phantasm -- not of course in its own right, for this pertains to the imaginative power, but inasmuch as the phantasm is an image of something already apprehended. He also stated the part of the soul to which [the memory?] of those that are in us pertains. For it pertains to the primum sensitivum, inasmuch as through it we have cognition of time.