Commentaria in Primam Partem Summae Theologiae

In the title, "proper" is distinguished against common. And it excludes, as is shown in the response to the second objection¹, not only the other divine persons, but also the nature itself.

II. In the body there is a single conclusion, responsive to what was asked and posited only implicitly: To be unbegotten is proper to the Father. – It is proved thus. The Father and the Son in God are principle not from a principle, and principle from a principle, just as among creatures this one is the first principle, that one the second principle: therefore the Father is made known in two ways, namely insofar as he is principle, by paternity and common spiration; and insofar as he is not from a principle, by not being from another: therefore by the esse of being unbegotten. And if you should understand tacitly that to be a principle not from a principle, or not to be from another, is proper to the Father, you conclude not only that being unbegotten belongs to the Father, which is explained in the text; but also that it is proper to the Father, which was what was asked, and which the text intended to determine.

The antecedent is made clear: because in the divine persons there is no prior and posterior, as will become clear below² – The first consequence, however, is proved thus: because a first principle in creatures becomes known in two ways, namely by relation to those things which are from itself, and by the negation of its being from another. – The second consequence, moreover, is proved thus: because not to be from another pertains to innascibility signified by the name unbegotten.

III. In response to the second, note that unbegotten, since it is composed of in- and begotten, is itself twofold. For the term in- is taken in two ways: purely negatively, or privatively; and the latter in several ways: either in a being (ens), or in a genus, or in itself—and only in this last way does it signify imperfection. Here, however, it is taken privatively with respect to a genus or principle, either personally or of the divine reality. – Likewise, begotten is taken in two ways: namely, properly, that is, from another by generation; and commonly, that is, from another in any manner whatever.

Hence in the text five claims are made. First, that ingenerate taken in a purely negative sense is not proper to the Father. Second, that ingenerate taken privatively in itself does not belong to the Father. Third, that ingenerate taken privatively within the genus of a divine supposit is not proper to the Father: because it belongs to the Holy Spirit. Fourth, that ingenerate within the genus of principle taken personally is proper to the Father. And in these four acceptations the term generated is taken properly. Fifth, that within the genus of a divine thing, taking the term generated commonly, ingenerate is proper to the Father: since he alone is in no way from another; for the essence, although not simply so, yet as it is in the Son and the Holy Spirit, is from the Father.

IV. In response to the fourth, note that the text assigns two reasons why there cannot be two unbegotten persons in God; in keeping with that saying of Hilary, since there is one God, there cannot be two who are unbegotten, assigning the unity of the divine nature as the cause of the unity of the unbegotten person. The first inference of the text is this: because in every nature one must posit a single first principle; and consequently, if there were several first principles, there would be several natures. – The second is because, if there were two unbegotten ones, they would be distinguished by a diversity of natures: for they would not be distinguished by opposed relations of origin; neither would be from the other, or from another.

V. Yet Scotus, in I, dist. II, qu. V, censured this second argument, on the ground that the middle term is not better known than the conclusion: for one who posited several unbegotten persons would not grant that they are distinguished by relations of origin. And Hilary, he says, indeed says this, but does not prove it.

But in truth the reasoning of Hilary, as well as that deduction drawn from the text, is not only reasonable but necessary. For either there is no distinction of persons in God, as the philosophers say: and thus there is only one ungenerated person. Or there are three persons, as the Catholic faith teaches: and thus, since a distinction through absolutes is unintelligible, it remains that it can be only through an order of origin. Hence the middle term is better known than the conclusion: just as it is better known that there cannot be a real distinction of persons in the absolutes without diversity of perfection. But Scotus, having conceived the act under a passion, which he was to expound in dist. XXVI of the same, seems to have said this: on which matter there will be discussion below³.