Reply to David Burrell

In this reply, let me just briefly react to what seems to be David’s main objection to Aquinas’s conception reconstructed in the paper. Since the objection does not concern the faithfulness of the reconstruction, I take it that I can rely on Aquinas for further support (and, if a molehill can support a mountain, he can also rely on me).

But first, here is what I take the objection to be. According to Aquinas, actiones sunt suppositorum, that is, it is only subsistent entities that can properly be said to perform actions. They have their active principles, by which they perform those actions, and which are instrumental in performing those actions, but the actions are properly attributed only to the suppositum, and not to the active principle. As he says: "Actions pertain to supposita and to wholes, but, strictly speaking, not to [their] parts and to [their] forms. For it is not a proper expression which says that a hand hits, but that a man does with his hand, and neither is it a proper locution which claims that heat heats, but that which says that the fire heats by its heat." (Actiones autem sunt suppositorum et totorum, non autem, proprie loquendo, partium et formarum, seu potentiarum, non enim proprie dicitur quod manus percutiat, sed homo per manum; neque proprie dicitur quod calor calefaciat, sed ignis per calorem. ST II-2 q. 58, a. 2) Now, Aquinas also insists against Averroes that what performs the action of thinking is the human person, or in David’s somewhat anachronistic formulation, ‘the self’. But this ‘self’, the whole human person constituted from body and soul, cannot be identified with his or her soul, since, as Aquinas would put it: nulla pars integralis praedicatur de suo toto – an integral part cannot be predicated of its whole; that is to say, any predication to the effect that this person is his or her soul has to be false. However, according to Aquinas’s doctrine of the immortality of the human soul, the reason on the basis of which we can conclude that the intellective soul survives the death of a human person is that the intellective soul has an immaterial act, namely, thinking. But then it is unclear how Aquinas can reconcile his doctrine of the immortality of the intellective soul, which requires the attribution of the immaterial act of thinking to this soul, with his insistence against Averroes that it is not this soul that does the thinking, but rather the whole human person by means of his or her soul. Indeed, in general, how can Aquinas maintain his apparently paradoxical doctrine that a human soul is both an inherent form, by which [quo] a human being thinks and lives, and a subsistent entity, that which [quod]has thinking as its own immaterial act, on account of which it lives an immortal life? – after all, aren’t the notions of inherent and subsistent being directly opposed to each other, as Siger of Brabant most notably claimed?

Although strictly speaking this issue lies beyond the rather limited scope of the original investigation of the paper, which excluded from its consideration the specific problems directly related to the immateriality of the intellective soul, this problem is clearly one of the most crucial issues in the broader context of Aquinas’s conception. So I am absolutely willing to take this opportunity to expand the scope of the original inquiry, to show how Aquinas’s conception reconstructed in the paper can handle also this problem. To be sure, I do not think that this reply will provide "the end of the story". On the contrary, I expect that what I am about to say will provoke further, and even broader questions –– but then, such is the nature of philosophy.

But first let me stress again, as I did in the paper, that here I am not concerned with showing the actual truth of Aquinas’s claim concerning the immateriality of the human intellective soul (although I do believe that his claim is true in its intended sense). Rather, here I will investigate only its meaning and its pertinent consequences. After all, this is all we need to see whether the problem in question can receive a consistent solution within Aquinas’s framework.

What does it mean, then, to say that the intellective soul is immaterial? Clearly, this claim cannot mean that the intellective soul does not have matter as its integral part, because this would not distinguish it from any other form, for no form (that is, a forma partis, as opposed to a forma totius) has matter as its integral part. But this claim cannot mean either that it does not exist in matter, for the intellective soul is not a separate substance. On the contrary, it is the substantial form of the human body. Indeed, as has been expounded in the paper, that the soul is the substantial form of the body means that the act of being of the soul is the same act as the act of being of the body, which is nothing but the life of the human being. But this seems to go directly against the claim that the intellective soul can possibly survive the body, since if the act of being of the soul is the life of the human being, then it seems that the end of the life of the human being should be the end of the act of being of the soul, that is, with the death of the human being the soul should perish as well.

It is at this point that Aquinas’s discussion of how the immaterial act of thinking pertains to the intellective soul as its proper act, and to the whole human being on account of the soul, becomes crucial. For the immaterial act of thinking, being immaterial, cannot be directly an act of the composite substance. It has to have as its immediate subject an entity which itself does not contain matter as its integral part. But this is the intellective soul. However, if the soul is the immediate subject of an act, which is therefore its proper act, then it has to have subsistent being, since we agreed at the beginning that properly speaking only subsistent beings can have their proper acts. So the soul has to have a subsistent act of being. But it cannot have any other act of being, so this subsistent act of being is also the soul’s inherent act of being, its act of informing the body. But this act is also the subsistent act of the whole composite, since there is only one substantial act of being in any composite, which is also the act of being of any of its essential parts. What remains, then, is that there is one substantial act of being here, which pertains both to the composite and to its substantial parts, but in different senses, and to one part, namely, to the intellective soul in two of these senses at once. OK, how is this possible?

Well, when we say that a certain significate of a certain predicate belongs to its suppositum in one sense, or another, then this means that this significate is signified by this predicate in this suppositum as belonging to the range of one signification, or of another signification, of the predicate in question. But of course there is nothing impossible in the claim that one and the same term which has different significations should have one significate in one of its supposita, but such that this significate belongs to the ranges of two of its different significations at the same time. Now this is the case here. The predicate ens in the sense in which it signifies the act of being of subsistent supposita signifies the act of being of this human being, and of that horse, and of that tree, etc. In the same sense, however, it does not signify the act of being of the form of that tree, nor that of that horse, but, according to Aquinas’s claim, it does signify the act of being of the soul of this human being. It is only in another sense, namely, in the sense in which it signifies the act of being of substantial forms, that it signifies the act of being of the form of the tree and that of the form of the horse as well as that of the soul of the human being. [See transparency below for technical details.]

Thus, pace Siger of Brabant, there is nothing impossible in the claim that the human soul is an ens in both senses. However, this is precisely the claim that the human soul has being in both senses, namely, both ut quo aliquid est and ut quod est. But if this is not impossible, then it is not impossible either that the soul should have some act which is only its own, and is not an act of the composite substance. Still, since the soul is an essential part of this composite substance, any act which belongs to this part alone denominates the whole of which it is a part in accordance with the common rule concerning the denomination of a whole from its part. (In case this "common rule" is not so commonly recognized nowadays as it used to be among medieval logicians dealing with the fallacy of secundum quid et simpliciter, I have to insert a brief explanation here. According to the rule a whole is properly denominated by any attribute of its part which can denominate only the part in question. For example, if Socrates’ hair is blond or curly, then Socrates is properly denominated blond or curly, since the terms ‘blond’ or ‘curly’ can only denominate his hair. By contrast, if his hair is black, Socrates cannot on that account be denominated black, for the attribute ‘black’ could also denominate his whole body. The rule was interpreted as covering all sorts of integral wholes, and was widely used by theologians in explaining what sorts of attributes could apply to Christ on account of his two natures.) Accordingly, if, for example, walking is an action which strictly speaking can only belong to the legs, then we also have to say that, precisely for this reason, when the legs of a person do the walking, then the whole person is walking. (By contrast, if only your arms or legs are swinging, then on that account you cannot be said to be swinging, for that action could belong to the whole of your body as well – for example, if you are hanged; Happy Halloween!) So, if the soul does the thinking, and the soul alone can do it, then, as long as the soul is a part of the whole human being, the whole human being is also denominated by this act. Therefore, if it is true that only the intellective soul thinks and only the intellective soul of a human person can do the thinking, then, since the soul is a part of the human person, indeed, an essential part, it is precisely for this reason that we have to say that the human person thinks, at least, as long as he or she has his or her soul. However, when the soul gets separated from the body of the person in question, this means that the act of being of this person comes to an end. However, this need not mean that the soul’s act of being should come to an end. What this means is only that the act of being in question ceases to be the act of being of the composite and it also ceases to be the soul’s in the sense in which it belonged to it as to the form of the body. But the same act of being will still belong to the soul in the sense in which it belonged to it as to a subsistent being. So the soul can continue in its life, and can continue its operation that belonged to it as its own, but no longer in connection with the body. Obviously, this raises a huge number of further questions concerning the nature of this operation, but those questions already belong to another discussion.



Three senses of the term ‘body’ distinguished by Aquinas

body(1) = body1 – substantial, non-exclusive – genus of all bodies

body(2) – non-substantial – accident in the category of quantity, corpus geometricum

body(3) = body2 – substantial, exclusive – genus of non-living bodies, and name of a substantial part of living bodies

General semantic framework

SGT(P)(u)(t)Î WÈ {0}; W¹ Æ , 0Ï W; A(t)Í W

|Ps| f,t =T iff SGT(P)(f(s))(t)Î A(t), where f(s)Î W

Example of ‘bachelor’

SGT(1)(‘bachelor’)(u)(t) = SGT(‘holder of BA’)(u)(t) = bachelorhood(1) ¹

SGT(2)(‘bachelor’)(u)(t) = SGT(‘unmarried male’)(u)(t) = bachelorhood(2)

SGT(1)(‘bachelor’) ¹ SGT(2)(‘bachelor’)

‘Body’ as the name of the whole and as the name of a part

SGT(1)(‘body’)(Socrates)(t) = Socrates’ corporeity1 = SGT(‘man’)(Socrates)(t) = SGT(‘animal’)(Socrates)(t) ¹ SGT(3)(‘body’)(Socrates’ part)(t) = the corporeity2 of Socrates’ body(3) = the corporeity2 of Socrates’ body2

SGT(3)(‘body’)(Koh-I-Noor)(t) = SGT(1)(‘body’)(Koh-I-Noor)(t) = the corporeity1,2 of Koh-I-Noor = SGT(‘diamond’)( Koh-I-Noor)(t) = SGT(‘carbon’)( Koh-I-Noor)(t)

SGT(1)(‘body’) ¹ SGT(2)(‘body’)

Ens ut quo vs. ens ut quod

If at time t this man and this tree are alive, but at t’ they are dead, then the following propositions hold:

SGT(‘quo’)(‘ens’)(tree soul)(t) Î A(t)

SGT(‘quo’)(‘ens’)(human soul)(t) Î A(t)

SGT(‘quod’)(‘ens’)(tree soul)(t) = 0

SGT(‘quod’)(‘ens’)(tree)(t) Î A(t)

SGT(‘quod’)(‘ens’)(man)(t) Î A(t)

SGT(‘quod’)(‘ens’)(human soul)(t) Î A(t)

SGT(‘quod’)(‘ens’)(human soul)(t) = SGT(‘quod’)(‘ens’)(man)(t) = SGT(‘quo’)(‘ens’)(human soul)(t) = SGT(‘quod’)(‘ens’)(human soul)(t’) ¹ SGT(‘quo’)(‘ens’)(human soul)(t’) = SGT(‘quod’)(‘ens’)(man)(t’) = 0

SGT(‘quo’)(‘ens’)(tree soul)(t) = SGT(‘quod’)(‘ens’)(tree)(t) ¹
SGT(‘quod’)(‘ens’)(tree soul)(t) = SGT(‘quo’)(‘ens’)(tree soul)(t’) = SGT(‘quod’)(‘ens’)(tree)(t’) = SGT(‘quod’)(‘ens’)(tree soul)(t’) = 0

SGT(‘quod’)(‘ens’) ¹ SGT(‘quo’)(‘ens’)