7.  A Critical Evaluation of the Biological Version of the Central Anti-Abortion Argument

        This version of the argument runs as follows:

(l) All innocent organisms belonging to the biologically defined species, Homo sapiens, have a serious right to life.

(2) It is at least prima facie very seriously wrong to kill anything which possesses a serious right to life.

(3) Therefore it is at least prima facie very seriously wrong to kill an innocent organism belonging to the biologically defined species, Homo sapiens.        [From (1) and (2)]

(4) Any human fetus, embryo, or zygote is itself an innocent organism belonging to the biologically defined species, Homo sapiens.

(5) Therefore it is at least prima facie very seriously wrong to kill a human fetus, embryo, or  zygote.
                                                                                    [From (3) and (4)]

(6) Abortion involves the killing of a human fetus, embryo, or zygote.

(7) Therefore abortion is at least prima facie very seriously wrong.
                                                                                    [From (5) and (6)]
 

7.1  Three Objections to the Biological Version of the Anti-Abortion Argument

        The crucial objections to this version of the central anti-abortion argument both concern the first premise:

All innocent organisms belonging to the biologically defined species, Homo sapiens, have a serious right to life.

        Three objections are especially important.  The thrust of the first is that this premise cannot be correct, since there are clear-cut counterexample to it.

        The thrust of the second is that it can be shown that this premise cannot express a basic moral principle, and that, because of this, the present argument needs to be expanded to make explicit the underlying, basic moral principle that is involved.  Doing so, however, involves shifting to some other version of the anti-abortion argument - such as one that appeals to the presence of an immaterial soul, or one that appeals to capacities, or one that appeals to potentialities.  The upshot of this second criticism accordingly, is that the biological version of the central anti-abortion argument cannot be a stand alone argument: it ultimately reduces to one of the other versions of the central anti-abortion argument, and if those other versions fail, so then does the biological version.

        The third objection, like the second, starts out by arguing that the claim that all innocent organisms belonging to the biologically defined species, Homo sapiens, have a serious right to life cannot be a basic moral principle, but it then goes on to argue that when one attempts to derive that claim from basic principles, any such derivation will fail, either because the derivation employs a purely descriptive claim that is false, or because the derivation employs a moral principle that is not itself tenable, or because the premises being appealed to do not entail the claim that all innocent organisms belonging to the biologically defined species, Homo sapiens, without exception, have a serious right to life.
 

7.2 The Counterexample Objection

        First, then, the counterexample objection - the thrust of which is that there are cases where killing an innocent organism belonging to the biologically defined species, Homo sapiens, or letting one die, is not even prima facie seriously wrong.  These include:  (i) the case of an organism that has suffered upper brain death;  (ii) the case of an organism that has suffered whole brain death;  (iii) the case of an anencephalic infant.

        The argument, then, runs as follows:

(1)  Even though such human beings may very well be innocent, killing or letting die in such cases is not seriously wrong;

(2)  Therefore, such humans, although innocent, do not have a serious right to life.

(3)  Therefore it is not true that all innocent organisms belonging to the biologically defined species, Homo sapiens, have a serious right to life.

        In thinking further about some of these counterexamples, it is useful to consider a range of cases, and to ask what one's intuitions are about the moral status of killing, or letting die, in each of these cases involving innocent human beings:

Case 1:   A psychologically normal, and physically normal, individual;

Case 2:   A psychologically normal individual, but one who is temporally in need of a life-support system;

Case 3:   A psychologically normal individual, but one who is permanently in need of a life-support system;

Case 4:   A psychologically normal individual, but one whose lower brain has been destroyed, and who has an artificial lower brain.

Case 5:   An individual who has no mental life at all, and who never will, because he has no upper brain, but who remains alive because his lower brain, or brain stem, is undamaged.

Case 6:   An individual who has no mental life at all, and who never will, because he has no upper brain, but who remains alive because of an artificial lower brain.

Case 7:   An individual who has no mental life at all, and who never will, because he has no upper brain or lower brain, but who remains alive because of an external life-support system.

        The idea is to begin by considering the two cases that are furthest apart, and to ask whether they are morally different.  If one's intuition is that they are, one then considers intermediate cases, in order to isolate the relevant factor.

        Most people, when they do this, conclude that the moral divide is between cases 4 and 5.  That is to say, they view it is as being very seriously morally wrong to kill, or to allow to die, people falling under cases 1 through 4, but not those falling under cases 5 through 7.  This in turn strongly suggests that what is relevant in the counterexample cases is the permanent absence of any mental life:  it is this that makes it the case that one does not possess a right to life.
 

7.3  Basic Moral Principles and Non-Reference to Species

        The first objection involved the technique of counterexamples.  A second objection to the biological version of the central anti-abortion argument can be arrived at by using another important principle of critical thinking - one which involves searching for principles of greater generality.  To see how this works, let us consider a claim that analytically follows from the claim that all innocent organisms belonging to the biologically defined species, Homo sapiens, have a serious right to life - the claim, namely, that

(1)  The killing of an innocent member of our own biological species, Homo sapiens, is always in itself prima facie seriously wrong.

        The application of the technique of searching for principles of greater generality then involves finding another principle that is rather similar to this claim.  The simplest way of doing this is by appealing to logically possible cases.  Suppose, in particular, that the lovable extraterrestrial, ET, rather than being merely an illusion produced by skillful animators, was an actual living thing, that he and a number of other members of his species moved down to earth, and that some entered this country.  (With Immigration and Naturalization Service permission, of course - so that they would not be illegal aliens.)  Given that the United States is the home of capitalism, we can imagine an enterprising business person who decides that it would be a good idea to open up a new fast food chain - the Kentucky Fried ET chain, perhaps.  What would one say about that?

        Though one should usually be hesitant to speak for others, doesn't it seem likely that even most anti-abortionists would hold that such a business enterprise would not be acceptable?  And if asked why, isn't it likely that the response might well involve something along the lines of the following moral claim:

(2)  The killing of an innocent member of the ET biological species is always in itself prima facie seriously wrong.

        But now we have two distinct principles - expressed by (1) and (2) - advancing claims about cases where killing is seriously wrong.  The method of searching for principles of greater generality then involves attempting to find some more general principle that explains why these two rather similar principles are true, while some other possible moral principles - such as

(3) The killing of innocent carrots is always in itself prima facie seriously wrong

- are not true.

        But what could the more general principle be that underlies both the principle concerning the killing of innocent members of our own biological species, Homo sapiens, and the principle concerning the killing of innocent members of the ET biological species?  Presumably it will have to focus on something that would be common to members of the two species, and which is not shared by, for example, carrots, and which is also a morally relevant property.  What could such a property be?  The answer, surely, must involve some sort of reference to the type of mental life that both Homo sapiens, and members of the ET species, are capable of.

        Exactly what form  the underlying principle take is not clear at this point.  But here are two important alternatives:

The killing of an innocent individual that has the capacity of having a certain sort of mental life is always prima facie seriously wrong.

The killing of an innocent individual that has the capacity, or even the potentiality, of having a certain sort of mental life is always prima facie seriously wrong.

        In the present context, however, it does not matter which of these two alternatives - or other possibilities - is most plausible.  The crucial point is simply that the consideration of other possible species strongly suggests that the claim that the killing of an innocent member of our own biological species, Homo sapiens, is always in itself prima facie seriously wrong, rather than expressing a basic moral principle, must be derived from some principle concerning he morality of killing which does not refer to any particular species, and which thus explains both why it is wrong to kill normal adult human beings, and why it would also be seriously wrong to kill non-human beings comparable to ET.

        The conclusion will then be the same with regard to the claim that all innocent organisms belonging to the biologically defined species, Homo sapiens, have a serious right to life.  It, too, must be derived from some more basic principle that is free of all reference to any particular species - some principle such as one of the following:

All innocent organisms that have the capacity for a certain sort of mental life have a serious right to life

All innocent organisms that have the capacity for a certain sort of mental life, or the potentiality for acquiring that capacity, have a serious right to life

        But then the biological version of the central anti-abortion argument does no stand on its own: it needs to be expanded so that it explicitly incorporates, first, the more basic moral principle that is free of all reference to any particular species, and, secondly, the relevant derivation that is based upon that more fundamental principle.  When this is done, however, what started out as a distinctive, biological version of the central anti-abortion argument turns out to reduce, in the end, to one of the other versions of the central anti-abortion argument.  The biological version of the argument therefore stands or falls with those other versions.; it is not an independent argument.
 

7.4  Basic Moral Principles and the Derivation Problem

        The third and final objection to the biological version of the central anti-abortion argument follows on immediately from the second, as the thrust of the third objection is that once it is seen that the claim that all innocent organisms belonging to the biologically defined species, Homo sapiens, have a serious right to life cannot be a basic moral principle, and one then considers how it might be derived, it turns out that there is no satisfactory derivation of it.

        Developing this objection in a detailed way would take considerable time.  But if we briefly consider some possible derivations, the fundamental problem will be clear.

7.4.1  A Religious Derivation

One way in which one might attempt to derive the claim in question - that all innocent organisms belonging to the biologically defined species, Homo sapiens, have a serious right to life - from a more basic moral principle would be as follows:

(1)  All innocent organisms that have an immaterial, immortal soul that incorporates the capacity for thought have a serious right to life.

(2)  All innocent organisms belonging to the biologically defined species, Homo sapiens, have an immaterial, immortal soul that incorporates the capacity for thought.

(3)  Therefore, all innocent organisms belonging to the biologically defined species, Homo sapiens, have a serious right to life.

        Here we have a derivation that is valid,  But not, it seems, one that is sound,  since, as we saw earlier in connection with our preliminary evaluation of the religious version of the central anti-abortion argument, there is no good reason for thinking that adult human beings have immaterial souls that incorporate the capacity for thought, and, on the other, there are good reasons - involving our knowledge of the relation between complex neural networks in the brain and different psychological capacities - for thinking that adult humans do not involve such an immaterial, soul substance.

7.4.2  A Capacities Derivation

        Another way in which one might attempt to derive the claim, that all innocent organisms belonging to the biologically defined species, Homo sapiens, have a serious right to life, from a more basic moral principle is this:

(1)  All innocent organisms that possess the capacity for thought have a serious right to life.

(2)  All innocent organisms belonging to the biologically defined species, Homo sapiens, possess the capacity for thought.

(3)  Therefore, all innocent organisms belonging to the biologically defined species, Homo sapiens, have a serious right to life.

        Here, too, we certainly have a valid derivation, but once again the derivation involves a premise against which there is very strong evidence, since, on the one hand, scientific knowledge derived both from neurophysiological studies and experiments, and from ordinary knowledge of what happens when one's brain is damaged in certain ways by accidents or strokes, strongly supports the conclusion that higher mental functions, such as that of thinking, depend upon the presence of very complex neural structures in the brain, and, on the other, we know that humans in the earliest stages of their development have no brain at all, and that it is much, much later in a human being's development before the relevant neural structures are present that appear necessary if an organism is to possess the capacity for thought.

7.4.3  A Potentialities Derivation

        A third way in which one might attempt to derive the claim ,that all innocent organisms belonging to the biologically defined species, Homo sapiens, have a serious right to life, from a more basic moral principle is this:

(1)  All innocent organisms that have the active potentiality for acquiring the capacity for thought have a serious right to life.

(2)  All innocent organisms belonging to the biologically defined species, Homo sapiens, have the active potentiality for acquiring the capacity for thought.

(3)  Therefore, all innocent organisms belonging to the biologically defined species, Homo sapiens, have a serious right to life.

        Again, the derivation is logically valid, but here there are strong objections to both premises.  With regard to the first, we shall be considering those objections when we turn to the potentialities version of the central anti-abortion argument.  With regard to the second, the counterexamples set out above to the claim that all innocent organisms belonging to the biologically defined species, Homo sapiens, have a serious right to life also show that the second premise is false:  anencephalic humans infants and adult humans who have suffered whole brain death or upper brain death are members of our species who do not have an active potentiality for acquiring the capacity for thought.

        The upshot is that a number of natural attempts to derive the claim that all innocent organisms belonging to the biologically defined species, Homo sapiens, have a serious right to life from more basic moral principles that are free of reference to particular species are flawed, so unless some other derivation that is not unsound can be advanced, this third objection stands.
 

7.5  A Quasi-Biological Version of the Anti-Abortion Argument

        An argument which is closely related to the biological version of the central anti-abortion argument, but which does not involve any reference to the biologically defined species, Homo sapiens, can be set out as follows:

(l) All innocent organisms belonging to a species whose normal, adult members possess the capacity for thought have a serious right to life.

(2) It is at least prima facie very seriously wrong to kill anything which possesses a serious right to life.

(3) Therefore it is at least prima facie very seriously wrong to kill an innocent organism belonging to a species whose normal, adult members possess the capacity for thought.                [From (1) and (2)]

(4) Any human fetus, embryo, or zygote is itself an innocent organism belonging to a species whose normal, adult members possess the capacity for thought.

(5) Therefore it is at least prima facie very seriously wrong to kill a human fetus, embryo, or zygote.
                                                                                                                            [From (3) and (4)]

(6) Abortion involves the killing of a human fetus, embryo, or zygote.

(7) Therefore abortion is at least prima facie very seriously wrong.        [From (5) and (6)]

 
        The crucial premise in this argument is the first one - that is:

All innocent organisms belonging to a species whose normal, adult members possess the capacity for thought have a serious right to life.

What is one to say about this premise?

        The answer is that it is exposed to three objections.  First, the counterexamples that tell against the claim that all innocent organisms belonging to the biologically defined species, Homo sapiens, have a serious right to life - namely, the case of anencephalic human infants and human adults who have suffered whole brain death or upper brain death - also refute the claim that all innocent organisms belonging to a species whose normal, adult members possess the capacity for thought have a serious right to life.

        Secondly, is it plausible that it is a basic moral principle that all innocent organisms belonging to a species whose normal, adult members possess the capacity for thought have a serious right to life?  The argument here is a more subtle one than in the case of the claim that all innocent organisms belonging to the biologically defined species, Homo sapiens, have a serious right to life, for here it will not do to appeal to ET-style cases.  What one has to do is to pursue the very theoretical question of the type of content that a basic moral principle can have.  This was briefly touched upon earlier - namely, in Lecture 9 - and there I suggested that the following principle was plausible:
 

Basic moral principles never involve any purely physical properties.

        But why might one think that this principle was plausible?  One reason is that when one considers plausible derivations of less basic moral principles from more basic ones, it is very often the case that the less basic ones involve reference to one or more physical properties, whereas the more basic ones are free of such reference.  (Consider, for example, the derivation of the principle that it is wrong to pull a cat's tail from the principle that it is wrong to inflict needless pain.)

        Secondly, when one attempts to formulate very basic moral or evaluative principles, it is almost always the case that the principles that are put forward are expressed in psychological terms, and that they are free of all reference to physical properties.  Consider, for example, the following moral principles, each of which has been advanced as basic by some philosophers:  one should not break promises;  one should not lie; one should not inflict pain upon others; one should respect other persons; one should treat other persons as one would like to be treated oneself.  Or consider the following axiological principles - that is, principles concerning things that are desirable or undesirable:  happiness is good in itself; pain is bad in itself; the pursuit of knowledge is good in itself; friendship is good in itself.  All of these principles, both moral and axiological, are expressed in terms of psychological concepts: no purely physical concepts are involved.

        Finally, occasionally one encounters a principle which appears to be basic, but which involves reference to some physical property or relation.  Thus, for example, many people might be inclined to hold that it is a basic moral principle that it is wrong to kill innocent people, and the concept of killing, since it involves the idea of doing something to a body, evidently involves physical concepts.  But if one reflects further upon this example, I suggest that it becomes plausible that there is a more fundamental, underlying moral principle that does not involve any physical concepts.  One way of seeing this is to notice that many people believe that there could be non-embodied persons.  Suppose, then, that non-embodied persons existed.  What would be the moral status of destroying such persons?  Presumably it would be just as wrong as that of killing embodied persons.  But then isn't it plausible to hold that the following is a more basic moral principle:
 

It is wrong to end the existence of any innocent person.

This principle, however, does not involve any physical concepts.

        My suggestion, in short, is that when one encounters what may initially seem like plausible counterexamples to the claim that basic moral principles never involve any purely physical properties, further reflection will lead to a more general principle that does not involve any physical properties.

        The upshot is that there do seem to be good reasons for thinking that basic moral principles never involve any purely physical properties.  The concept of a species, however, is certainly a physical concept: it involves, for example, the idea of reproduction.  Consequently, there is good reason for holding that the claim that all innocent organisms belonging to a species whose normal, adult members possess the capacity for thought have a serious right to life cannot be a basic moral principle.  So here, too, as in the case of the biological version of the anti-abortion argument, we can conclude that the quasi-biological argument cannot be a stand alone argument: it must stand, or fall, with the soundness of some other argument that does not involve the concept of a species.

        Thirdly, and finally, suppose that A and B are both innocent individuals that belong to different species, and where A has, first, all of the psychological capacities that B possesses, and more, and, secondly, a mental life that is richer than what B has.   Or suppose, more dramatically, that C and D are both innocent individuals that belong to different species, and where C has both a number of psychological capacities, and a relatively rich mental life, whereas D has neither and psychological capacities, nor any mental life at all.  Does it seem plausible that B might have a right to life, but A not?  Or that D might have a right to life, but C not?  Neither of these is, I suggest, at all plausible.  But if the above principle were true, these things would often be the case, since B and D might belong to species whose normal members do possess the capacity for thought, while A and C might neither belong to such a species, nor themselves possess the capacity for thought.