In De ente et essentia D. Thomae Aquinatis commentaria

On the individuation and numerical multiplication of the intellectual soul.

Here there is doubt concerning the individuation of the intellectual soul, namely, by what it is individuated. Three things must be done in this question. First, Scotus’s opinion will be recounted. Second, St. Thomas’s opinion will be explained. Third, the arguments for the opposite will be answered.

As to the first, Scotus, in II Sent., dist. 1, last question, and in Quodlibet II, following his position concerning haecceities, holds that the soul is individuated by its own haecceity; and he argues thus against St. Thomas. That by which something is first in act outside a cause and the intellect is that by which it is first this; but the soul, like every entity especially absolute, is first in act outside a cause and the intellect through itself; therefore the soul is first this through itself. The major is proved because universality, or being-not-this, belongs to a thing only in the intellect. The minor is clear from the fact that a thing first withdraws from non-being through itself.

Moreover, every formal distinction, or distinction not through matter, is specific according to you: intellectual souls are formally distinguished, or distinguished not through matter; therefore they are specifically distinguished. The conclusion is false; therefore one of the premises is false. Not the minor, because separated intellectual souls lack matter; therefore the major is false, although it is the foundation of his position. But if you say that souls have inclinations to different bodies and are distinguished through these, the contrary follows: the soul is by nature first the term of creation, which as such is formally this, before it is united to matter; therefore by nature the soul is this before it is united to matter: therefore the soul is individuated, and not through union with the body. The antecedent is proved thus: that which can be without another, while the other cannot be without it, is prior, from Metaphysics V, text XVI. The soul can be without union to matter not only according to essence but also according to existence, but not without being the term of creation and being this; therefore by nature the soul is the term of creation and this before it is in matter.

If it is said that the soul is not this through actual union, or existence in matter, but through an aptitude to exist in it, this does not escape the difficulty, because an absolute nature is prior by nature to its very aptitude. For because the soul is this, it has this aptitude toward this, and the other aptitude is repugnant to it, and so forth, as the argument may be formed thus. What belongs to one and is repugnant to another of the same species does not belong per se to this one according to what is common to them; or at least it necessarily presupposes their distinction, namely, of this from that. But this aptitude belongs to this soul and is repugnant to that one; therefore it necessarily presupposes the distinction of this from that; therefore souls are not individuated by aptitudes.

This is confirmed. The formal account of aptitude is not toward itself, nor is it the account of a being in act; therefore it cannot be the individuating principle of the soul. The antecedent is proved as to the first part, because if it were toward itself, it could be understood as not toward another, as toward a term, which is false. The second part is likewise proved, because what necessarily requires something nonexistent is itself nonexistent in act; but aptitude is toward a nonexistent term; therefore its account is not the account of a being in act. The consequence is clear, because relative distinction presupposes absolute distinction: because the soul is this, it therefore has this aptitude, and not conversely; and because this soul is singular with actual, or in-act, singularity, it is not this through an aptitude toward this body. Such is what these men think concerning this matter.

But following Peripatetic foundations, we say that the soul is individuated by substantial commensuration to this body, and that this soul and that soul are distinguished by their commensurations to this and that body. The proofs of this were given above, when it was deduced that numerical distinction can originate only from quantity. Hence it is now enough to explain how what we say is so. Commensuration is taken in two ways. In one way, for the relation of commensuration; in another, for the substantial coaptation of the thing itself. In the first way, commensuration is essentially a relative thing and belongs to the genus of relation. In the second way, it is an absolute thing and belongs to the predicament of the thing commensurated: for it is essentially the same as that thing, differing from it only in account. I say the same likewise of inclination, aptitude, coaptation, signification, and similar terms, which are assumed to express the point at issue. The absolute too is now taken in two ways. In one way, from the term; thus we say that substance, quantity, and quality are absolute beings. In another way, from the recipient or subject; thus none of the predicaments of accidents is absolute, for they are essentially receivable in substance. Therefore, when it is said that souls are individuated by their commensurations, this must be understood of substantial commensurations, which are absolute things with respect to terms, though not with respect to recipients, and not of commensurations that are relations, and so forth. For just as it belongs to the essence of soul in general to be essentially proportioned to an organic physical body, which is placed in its definition, so it belongs to the essence of a human soul to be commensurated to a human body: for it is the perfection of a human body in such a way that it is not the perfection of an ox’s body. So too it belongs to the essence of this soul to be commensurated to this body; and thus commensuration to a human body does not follow upon the human soul, but constitutes the human soul itself. For the soul of a man first differs from the soul of an ox by this: the former is the proper act of a human body, while the latter is the proper act of an ox’s body. Now it is clear that to be the proper act of a human body is the same as to be a substance substantially commensurated to its perfection. Thus the substantial commensuration of this soul to this body does not follow upon this soul, but constitutes this soul as this; for this soul is substantially the proper act of this body. Hence this soul first differs from that soul because this is the proper act of this body, while that is the proper act of another. This is what St. Thomas teaches in II Contra Gentiles, chapter LXXXI, in the Questions on the Soul, and wherever he speaks of this matter.

This proposition is in agreement with Aristotle’s principles. For in the first book of On the Parts of Animals he teaches that the proper differences of something divided must distinguish it per se insofar as it is such. For example, the proper differences of animal should not be white and black, which do not divide animal insofar as it is animal. The identity of animal stands together with their diversity. Nor should they be capable of navigation and capable of flight, because these do not diversify the sensitive nature per se; rather, the differences should be this sort of sensitive thing or that sort. For animal, insofar as it is animal, is constituted together with the sensitive, and is diversified per se only through differences of sensing. Therefore, since the soul, insofar as it is such, is essentially the act of a physical body, it is divided by its proper differences according as it is the act of such a body or such another; and again, the act of such a body, for example a human body, is divided by proper, though material, differences according as it is the act of this body or that. Souls, therefore, are individuated by substantial commensurations that are not absolute from their recipients, just as souls themselves are essentially not absolute from the bodies they perfect and receive them.

Failure to consider this is the cause of the error of those who want to judge everything in the same way, as the Scotists do. Since they do not consider the proper natures of things and want to make things commensurate with their concepts, it happens that they pronounce the same judgment concerning the individuation of everything, and belong to the number of those of whom it is said in On the Heavens II, text LXXX, that they inquire until they have no contradiction with themselves.

Having seen these points, we must proceed to the solution of the arguments.

To the first it is said that the major is false. Although every thing posited outside the intellect and a cause is this, nevertheless it is not first this by the same principle by which it is first a being. For it is first by its very being; but it is first this by haecceity. Many things accompany one another inseparably, yet are not first possessed by the same principle. Thus every being other than God exists outside the intellect and a cause, and is dependent; nevertheless it is not by the same first principle that it exists and that it depends. The minor too is false: a thing is not really distinguished from itself first through itself, but through actual existence, as was explained above, and so forth.

To the second, the minor is denied. For two separated souls are not formally distinguished, but through matter, although they are pure forms abstracted from matter. It is one thing to say, “Every formal distinction is specific,” and another to say, “Every distinction of forms is specific.” For formal distinction, since it is that which consists in definitive principles, is specific; whatever things have diverse definitions differ in species, and at least have different ultimate differences, whose diversity suffices for specific diversity. But there is no such distinction between Socrates’ soul and Plato’s: they have the same definition. A distinction of forms, however, wherever division among forms occurs, is found in two separated souls because they are coapted to different bodies. Hence the account is not the same for them and for other separated substances, which cannot be united to bodies. Thus the answer given there is good, provided it is rightly understood in the manner explained: souls are distinguished by substantial inclinations to different things.

To the first objection against this, it is said that it does not establish the intended conclusion. It concludes, “Therefore by nature the soul is this before it has actual union with the body,” whereas it ought to conclude, “Therefore by nature the soul is this before it is coapted or inclined to this body.” For we do not say that the soul is formally individuated through actual union with the body, but through substantial coaptation to this body. That this is naturally prior to the actual union is clear from the fact that everything here per se terminates creation, and not the soul existing in this; and from the fact that inherence presupposes existence, while particular existence is more immediate than inherence. Hence the answer recited there is good, though with a grain of salt. For we say that souls are formally individuated through substantial aptitude or commensuration; but through actual union with the body conditionally, that is, as a condition without which not: and because the formal account of a thing is naturally prior to a condition without which not, therefore, and so forth.

The answer to the argument against this is clear from what has been said. For it assumes the falsehood that the nature of this soul is prior to its substantial aptitude. Hence the major of the argument formed there for the second disjunctive part is false, namely, that “whatever belongs to one and is repugnant to another of the same species necessarily presupposes their distinction.” It can happen that it does not presuppose their distinction, but makes their distinction. Just as what belongs to one species and is repugnant to another species of the same genus need not presuppose the distinction of those species, but it is enough that it make their distinction. For example, rational belongs to man and is repugnant to a lion, while irrational belongs to a lion and is repugnant to man; yet rational and irrational do not presuppose the distinction of man and lion, but make it. Therefore add under that major: “But the haecceity of Socrates’ soul belongs to it and is repugnant to Plato’s soul; therefore haecceities presuppose the souls already distinct.” In this way you will recommend to the Scotists the force of their argument, and so forth.

To the confirmation, when it is said that the account of aptitude is not toward itself, I say that the account of substantial aptitude of which we speak is toward another, but not toward another as toward a term, rather as toward a recipient. The proof against this does nothing: I concede that it can be understood as not toward another as toward a term, but not as not toward another as toward a recipient, just as quantity and quality are absolute from a term, but not from a subject.

To what is placed second in the antecedent, namely, that the account of aptitude is not the account of a being in act, I say first that this is false. For the aptitude for laughing, namely risibility, has the account of a being in first act, although it has potency for second act. Both propositions of the proof are false. The major, namely, “What necessarily requires something nonexistent is itself nonexistent in act,” is false because every active potency in first act merely requires its operation not yet to exist, and yet the potency itself exists in act. The minor is false because the substantial aptitude of the soul for the body does not exclude the body; rather, it is the composition from contraries that makes the soul’s aptitude exist without actual union.

Second, I say that we equivocate concerning aptitude. For this aptitude that we understand in the soul is nothing other than the commensuration, or substantial sealing, of the soul itself to this body, which is clearly in act both while it is united to the body and while it is separated from it, as is clear in the example given above concerning wax. The argument proceeds as though this aptitude were something potential, awaiting something to reduce it to act, and so forth. As to the consequence, it is clear what must be said: it is not such a relative distinction, but an absolute one relative to what is received, and so forth.

And because in these substances quiddity is not the same as existence, they are orderable in a predicament; for this reason genus, species, and difference are found in them, although their proper differences are hidden from us. In sensible things too the essential differences themselves are unknown to us; hence they are signified through accidental differences, which arise from the essential ones, just as a cause is signified through its effect, and as biped is posited as the difference of man. But the proper accidents of immaterial substances are unknown to us; hence their differences can be signified to us neither through themselves nor through accidental differences.

In this third part of this chapter, St. Thomas, about to explain how the quiddities of separated substances are related to the logical intentions—namely genus, species, and difference, and so forth—settles the matter with four observations, excluding two objections afterward. He therefore first proposes this conclusion: Intelligences are in a predicament. He proves it thus: everything in which existence differs from essence is in a predicament; intelligences are of this kind; therefore, and so forth. The minor was proved above. The major can be proved thus: everything having limited existence is in a genus. For if it has limited existence, it is determined to some definite genus; but what is determined to no definite genus subsists through itself—so whence or how could it have limited existence? Moreover, every being in which existence is distinguished from its essence has limited existence, as was explained above; therefore everything of this kind is in a predicament. From this it follows as a corollary that they have genus, species, and difference. He adds that their differences are hidden from us. He does so to answer the doubt of someone who might say: how do you know that there are differences in them if we do not know them? To know of them immediately the question whether they are, and to be ignorant of the question what they are, are different. We know, I say, that there is a difference in them, but what those differences are is hidden. The differences of intelligences are hidden in themselves, because it is common to all substances to have their proper differences hidden in themselves. In this they agree with lower substances: their differences are hidden according to accidental properties, which are their passions, because these exceed the natural power of the human intellect, which is related to what is most manifest in nature as the eye of an owl is to the light of the sun. In this they differ from sensible substances, whose proper differences are signified by the names of their properties, just as causes are signified by the names of their effects. Hence the differences of intelligences are altogether unmanifest to us with respect to what they are, and so forth.