Commentaria in Primam Partem Summae Theologiae

In the title, note that, since each art uses its terms as they have been accustomed to be received in that art—and this is permissible, as is clear ¹, because the signification of names is a matter of convention, and all the more so their transference from one signification to another—since, I say, this is so, it is reasonable that the prince of all sciences, sacred Theology, should also rejoice in its own vocabulary. And therefore the question here concerns the name "person" not in any way whatever, but as it is in use among theologians: for it is evident that "person" is taken one way among the canonists and another way among others. And for this reason Lorenzo Valla ignorantly accuses Boethius of having given a bad definition of person: for it is in fact an excellent definition, as will become clear in this article, if person be understood in this way—which was also what Boethius himself intended.

II. In the body he does three things: first, the dignity of the individual substance is shown; second, the dignity of the individual rational nature²; third, the question raised is answered³.

As to the first, he intends that the individual of substance agrees with the individuals of all the genera in this, that each is a particular or an individual; it differs, however, from the others in two respects, namely as regards the cause of individuation and as regards the special character of its name. For substance is individuated through itself, whereas an accident is individuated through its subject, which is substance: which is made manifest in this whiteness. And therefore the individual of substance has received a special name, and is called hypostasis, or first substance: which is not found in the genera of accidents.

III. Concerning these statements, several doubts arise. First, on the side of substance: how it can be true, in the doctrine of St. Thomas, that substance is individuated through itself; since in him⁴ numerical distinction belongs first to quantity, and through it to material substances and the rest. And thus, since the distinction from others pertains to the notion of an individual substance, it follows that substance is individuated, as regards its intrinsic principle of distinction, by quantity; and not through itself, as the text says.

IV. Second, there is a doubt on the side of the accidents. For quantity is individuated of itself, as is clear from the definition in Book V of the Metaphysics⁵: "A quantum is that which is divided into the things present in it, each of which is by nature this particular one". And in mathematical abstractions it is manifestly evident that this line, etc., exists with no imagined subject.

The letter also gives rise to some doubt in that it expresses the individuating accident as being a substance; since it is manifestly clear that this conditional is true: if whiteness were in this quantity without a substance, it would be this. And consequently that categorical proposition is false.

V. Third, there is a doubt also on the side of the accident: how is it to be understood that it is individuated by the subject—namely, whether intrinsically or extrinsically. That is, whether, when one says this whiteness, the subject is contained intrinsically in the this, or extrinsically, in the way that nose falls within the signification of snubness or of a snub nose. For if it is contained only extrinsically, it follows that the accident is individuated by itself intrinsically. But if it is contained intrinsically, it follows that this whiteness is not a being nor one per se, and consequently belongs to no genus. And on this account it is wrongly said in the text that in every genus there is found both universal and particular.

VI. To the first point⁶ of these, insofar as it concerns this text, it can easily be said that here the discussion is not about substance of a certain kind, say material substance, but about substance absolutely: and hence, about all individuals of substance, not insofar as they are individuals of such or such a substance, but insofar as they are individuals of substance. First, because only thus is the discourse formal. Second, because thus the intended difference between an individual of substance and an individual of accident is properly interpreted. For these differ first, insofar as one is an individual of substance and the other an individual of accident, by the common features shared by all individuals of substance on the one hand, and by the common features shared by all individual accidents on the other: for such are those things that belong to these, insofar as they are individuals of this kind.

VII. And by this the answer to the remaining doubts is clear⁷. For the objections brought forward concerning the individuals of accidents do not concern them insofar as they are individuals as accidents, but insofar as they are individuals of such accidents, namely of quantity, or of a quality that affects substance mediately, as whiteness does, which is adduced in the text by way of example, so that learners may understand. It therefore stands that the truth of the text is unshaken: that the individual of substance, as such, is individual through itself, since it is evident that, as such, it has no dependence upon an accident; and that the individual of an accident, as such—since it must depend on no other subject than substance—is individuated through the subjecting substance.

VIII. To the final doubt, however⁸ it must be said, on account of the reason touched upon in the objection, that this accident does not include its subject intrinsically, but by way of an addition: so that, just as in the definition of an accident the subject is included, not as something intrinsic to its essence, but by way of an addition, so in the definition of this accident, were it to be defined, this subject would be included by way of an addition, and not intrinsically. Nor does this conflict with the text in the assigned difference. For just as an accident cannot be understood without a dependence upon a subject, so neither can this one be understood without a dependence upon this subject. But substance as such includes no dependence upon anything extrinsic. And therefore substance is individuated of itself, whereas an accident is individuated through substance.

IX. But concerning material substance, and how such accidents are individuated, that is another matter: there will be a special question about this. Now know, however, that in my view material substance is individuated through matter under determinate dimensions, as through its proper and intrinsic principle—not only constitutive but distinctive; for it is chimerical to separate these acts in reality. By matter under determinate dimensions I do not mean, as I once explained in my commentaries on Being and Essence⁹, matter with a potency toward quantity; since that potency, as is clear in Book XII of the Metaphysics¹⁰, in the treatise on the principles of the Categories, is in the genus of quantity; and thus Socrates would not be one per se. Rather, I understand matter distinct in number, not as the subject of quantity, but as prior by nature to it, its foundation, root, and cause; so that matter itself is prior in itself to being thus distinct than to being quantified, so that the effect may be proportioned to its cause. For the numerical distinction by which Socrates is distinguished from Plato, insofar as they are these men, is not a quantitative distinction, but the foundation of quantitative distinction. And likewise the distinctive principle of this man from that one, as such, is the root and foundation of quantity, and consequently of the distinction following upon it. This, however, is matter, which is the other part of the composite first terminating substantial generation in the nature of things, at the first instant of nature, before the adherence of accidents. For then there must be something singular, distinct from the universal, and an ens and one per se—which cannot be understood without a constitutive principle in this esse: for by the same thing each thing is this, and is distinguished from the rest.

X. Nor do I therefore deny that greatest doctrine, held from the senses of Aristotle and St. Thomas, namely that numerical material distinction belongs first to quantity, and consequently through it to the rest, according to the teaching of Posterior Analytics¹¹. For participating in the nature of that to which something first belongs can occur in many ways; nor is it necessary for that nature to be saved formally in all its participants, as we showed in I Poster.¹². Now matter, which is the root and foundation of quantity, is not, even in that prior respect, outside the participants in the nature of quantity: indeed, to speak more accurately, it is as if pre-possessing the nature of quantity. And since pre-possessing is more than participating, if participants in some nature can in any way bring about its effect, how much more will those who pre-possess that nature be able to do so? For every effect belonging first to something must be brought about by that thing in itself, or by its participants, or by those who pre-possess it; as appears inductively also in formal effects, in the vegetative and the sensitive and the like. Although the distinction of which we speak is not a formal effect of quantity, nor does matter of this kind thus contain quantity: yet these things have been said so that readers may understand. The remaining matters concerning this subject are treated there.

XI. That, according to¹³, the dignity of the individuals of rational nature among all the individuals of substance is shown, likewise with respect to two things. First, with respect to the mode of being (esse) as the principle of operations: namely, that the individual of rational nature alone has dominion over its own act. And that this pertains to the dignity of the individual, the text proves from this, that actions belong to singulars, I Metaphysics¹⁴ — Second, with respect to the specialness of the name: because the others, insofar as they are individuals of such a nature, for instance an irrational one, did not merit a proper name; but this has received a special name, which is "person," on account of the aforementioned dignity. — And thus we have both the proposed dignities and the answer to the question about the name of person, in what is said, that it is the name of the individual of rational nature. There remains therefore the third.

XII. As to the third point, therefore, the question is answered with a single affirmative responsive conclusion, though implicitly: The definition of person is adequate. – And it is shown thus. The aforesaid definition explains both properties of an individual of rational nature; therefore it is adequate. ¹⁵

The antecedent is explained. For that which belongs to it insofar as it is a singular substance, he explains by ly an individual substance; but that which belongs to it insofar as it is a singular of rational nature, he explains by ly of rational nature. For since the individual of the lower is also the individual of the higher, it must possess the conditions of both. And again, since two things are attributed to the individual, namely to be (esse) and to act (for universals have neither), he signified individuals by means of both: first, namely, by being (esse), second, by acting.

XIII. In response to the first and third, you have that something real, namely a mode of subsisting, beyond the specific nature, belongs to the individuals of substance, as we declared more fully in The Categories¹⁶.

In response to the second, you have that individual substance is not taken here as distinguished against universal substance, but as distinguished against the essence of substance, both universal and particular. For only this is called first substance, supposit, person, etc. – But what first substance or supposit adds above this humanity, when the union of the Word with human nature is treated of, will be discussed ¹⁷. For the purpose, however, it suffices to know that it adds every kind of incommunicability, so that it can neither be common nor be assumed: for on account of the former, deity is not a supposit; and on account of the latter, this humanity is not a supposit.

XIV. In response to the fifth objection, note that from this you have that it does not follow from this definition of Boethius that the soul is a person, as Scotus wished, in I, dist. XXIII¹⁸, not penetrating what first substance, which is here called individual, imports.