Commentaria in Primam Partem Summae Theologiae

In the title, note that the intention of the text is not only to discuss whether there are more persons than three, but also whether there are fewer, say only two. And this is clear both from the statement of the questions at the beginning of this question; for the text says there that secondly it must be asked how many there are; and also from the responsive conclusion set forth and adduced in the body of the article; for it is an exclusive proposition, namely, The divine persons are only three; for the truth of which it is evident that it must be verified that they are neither more nor fewer.

II. In the body, a single exclusive conclusion answers the question: It is necessary to posit in the divine only three persons.

And it is proved at once with respect to both exponents, thus. The several divine persons are several subsistent relations, really distinct from one another by relative opposition alone: therefore all opposed relations belong to distinct persons, and relations not opposed belong to the same person: therefore paternity and filiation pertain to two persons, and so paternity is the person of the Father, and filiation is the person of the Son. – Then further: therefore the other two relations, namely spiration and procession, which are opposed neither to either of the foregoing but to each other, do not both pertain to one person: therefore either one of them belongs to both of the said persons, or one belongs to one and the other to the other. But procession cannot belong to both: because the procession of the intellect would proceed from the procession of love. Therefore spiration belongs to both, as being opposed to neither of them. Therefore procession belongs to the other person. Therefore there are only three persons, namely the Father and the Son and the Holy Spirit.

III. Concerning this argument, a not insignificant doubt arises about the manner of proceeding: for it clearly appears diminished and truncated. First, because it proposes a disjunctive, namely, that spiration and procession are so related that either one of them belongs to the Father and the Son, or one to the Father and the other to the Son: and yet it does not examine the second part of the disjunctive, upon whose examination depends whether the persons are fewer than three. Second, because it also proposes a negative having two parts, namely, that procession does not belong to the Father and the Son, or to either of them: and yet it proves it only with respect to the first part, as the reasoning of the text clearly shows, and the words subjoined attest, namely, that if the person generating and the person generated were to proceed from the spirating one.

IV. Concerning the same argument there is also a doubt, since it seems to involve contradictions. On the one hand, it is said that only relative opposition really distinguishes in the divine, and that the relations of the second combination, namely spiration and procession, are not opposed to those of the first, namely paternity and filiation; on the other hand, it is proved that procession is really distinct from paternity and filiation. For from these I argue as follows. From the first statement, only relative opposition really distinguishes; but procession is not relatively opposed to paternity or filiation, by the second statement; therefore it is not really distinguished. And conversely: procession is really distinct from paternity and filiation; therefore it is relatively opposed to them. Or else, therefore, not only relative opposition really distinguishes in the divine. All of this is against the text. Therefore.

V. To the first doubt¹ it must be said that it was fitting to propose explicitly for discussion all the members, lest any of them seem to have been consigned to oblivion; and so that it might be shown from the conclusion of the process that all of them had been discussed implicitly. The manner in which, without defect, all are understood to have been discussed in this brief letter is as follows. Once it had been laid down in general that one of them (namely spiration and procession) belongs to both (namely the Father and the Son), or one to one and the other to the other; and once it had been added in particular that procession belongs neither to both nor to either; he began to pursue the first part of both the first and the second proposition: namely, whether one belongs to both (that is, to the Father and the Son). And examining this, he began with procession; and he inferred the negative part, namely that it does not befit both. And proceeding by the same path, he consequently concluded concerning the other, namely spiration, that it befits both. And so, with the first member first proposed having been completed first, as the right order demanded, there was no longer need to discuss the remaining proposed members: since from the affirmation of the first, together with what had been premised in this process, they are manifestly found to be excluded. For it was said that spiration and procession cannot pertain to the same person; and now it was laid down that spiration befits the Father and the Son; therefore it manifestly follows that procession befits neither both nor either, and that it cannot be that one befits one and the other the other, which had been proposed.

Nor does it stand in the way of this argument as thus expounded, that with the letter of inference it concludes, saying: It remains therefore that spiration. For that inference does not regard all the things said before, but the common canons premised here, and the force of the duality of relations, namely procession and spiration. And it intended that, because, if no opposition stands in the way, one of these is identified with each (namely the Father and the Son), and procession cannot be identified with each, it remains that spiration is identified with each, since it has no opposition to either. Thus indeed the letter infers, and not absolutely, without the addition of the aforesaid middle term, as is evident to one attending.

VI. To the second doubt, however² it is briefly answered that, since the relative opposition distinguishing the divine persons is according to the order of origin, things can be said to be relatively opposed there in two ways: namely by reason of relation or by reason of origin. Things opposed by reason of relation are only correlatives, such as Father and Son with respect to each other, and spirating and proceeding with respect to each other; but things are opposed by reason of origin whenever they are so related that one must be from the other, and not conversely. I say therefore, first, that the second combination is not opposed to the first by reason of relation: and this is what the text intends, saying that neither of these oppositions has opposition to any of those. Second, that procession is opposed to both by reason of origin: because the origin of love is from the intellect, and not conversely. And this the text intended when it excluded procession from the Father and the Son: for this opposition is a relative opposition of origin. Spiration, however, has no opposition either by reason of relation or by reason of the order of origin with respect to paternity and filiation: and therefore it rightly coincides with both. And thus, interpreting relative opposition under different aspects, there is no implication in this process, as is clear from what has been said: and it has been effectively proven that the divine persons are three only.

VII. In response to the second objection, note that, if you wish to see completely why the procession of intellect and nature coincide, but not that of the will, you should consider the three differences set out in Qq. de Potentia q. X, art. 2, ad 11.