Commentaria in Primam Partem Summae Theologiae

Concerning the order of this question and the preceding ones, there is a doubt. For unity is prior to being (ens) than simplicity and immutability, and the other things treated from question III up to this point; therefore unity is treated inconveniently in the last place. – The antecedent is proved: because every being (ens) is one, but not simple nor immutable; and that is prior from which the consequence is not convertible.

II. To this it is said that, just as the treatise on the nature of the animal according to all its quidditative predicates precedes the treatise on the unity of the animal, so the treatise on the divine nature according to all its quasi-quidditative predicates precedes the treatise on its unity: since unity is a quasi-passion of being (ens), and the unity of such a thing is a quasi-passion of that thing. Now the four things treated of thus far, after the question whether it is concerning the divine nature—namely simplicity and perfection, infinity and immutability—are contained within the breadth of quidditative predicates, as is evident inductively; and therefore they were treated of first. And for their completion, there have been inserted questions on goodness, on the existence of God in things, and on eternity. And so, with the quiddity as it were settled, he arrives at the first passion, namely unity. – That this was the Author's intention you can infer from the introduction to question III placed above in the text: for there these five things are proposed for treatment.

Nor does the objection raised stand in the way: for it is denied that unity is prior to the things said above. And in proof of this, it is said that that from which the consequence does not convert by reason of itself is prior, but not if it is by reason of another. For example, to be colored with respect to man is that from which the consequence does not convert, yet it is not prior to man, although it is a more common predicate: and this because colored is that from which the consequence does not convert, not by reason of itself, but by reason of its subject. For by reason of the subject it holds that he is a man, therefore he is colored, and not conversely. Hence that from which the consequence does not convert is prior, or includes something prior by reason of which the consequence does not convert. And so in the case at hand, one is not formally prior, but includes being (ens), by reason of which the sequel does not hold, it is one, therefore it is immutable, but rather conversely.

III. A famous title. – In the body, two conclusions. The first directly answers the question: "One" adds nothing above ens (being), not any thing, but only a negation of division. – It is proved: "one" signifies nothing other than being as undivided; therefore.

The second conclusion is a corollary: One is convertible with being. And nevertheless it is proved: the being (esse) of any thing consists in indivision; therefore. – The antecedent is proved in two ways. First, inductively, from the being of simple things and of composites. Second, from a sign, namely that each thing preserves its unity just as it preserves its entity. All this is plainly evident in the text.

IV. Concerning the first conclusion, a doubt arises from a twofold source: since Avicenna holds¹ that unity adds some thing above being (ens); and Scotus holds that it adds a certain reality. But because Avicenna's position is refuted by Aristotle in Book IV of the Metaphysics², and is disputed here in the text, Scotus's opinion must be treated, in Book IV of the Metaphysics³. Supposing, therefore, that unity signifies a passion of being (entis), he says that it formally imports something positive, really the same as the being itself; just as he universally holds that a passion is identified with its proper subject. And his followers there strive to prove this point in several ways.

First, the one formally, that is, as distinct from being (ens), is really identical with being: therefore it is something positive. The inference holds: because a negation cannot be identified with a real being. – Second, the one formally is outside nothingness, as being a passion of being: therefore it is positive. – Third, the one formally has the character of the first measure and principle of number: therefore, as before. – Fourth, the one signifies a perfection simply speaking: therefore. The antecedent is proved: both because in each thing itself is better than not itself, and because it is reduced to the supremely one, just as to the supremely good and just, etc.; for this is proper to perfections simply speaking.

V. To these things a brief reply is given. And first the antecedent is distinguished: for being the same occurs in two ways, namely positively and negatively. Now one thing is negatively the same as an entity: because it signifies not another nature, but the same in another way, as is said in IV Metaphysics⁴ And thus the inference is worthless.

With respect to according to, however, it is said that one being formally is not more outside of nothing than other privative or negative beings in the genus. It is therefore outside of nothing thus: and then the consequence is denied.

To the third argument, the consequence is denied: because to measure is common to positives and negatives. For not only in the genera of being (ens) does the most simple measure the rest, but also in the genera of diseases and sins, as is clear in moral matters; for the least among the vices of gluttony is the measure of the rest. And the least absolutely, that is, one, measures multitude absolutely. Yet each of these is a negative, namely multitude and one, as is said in the text of this question. Now I understand transcendent number and absolute multitude to be the same thing. And therefore it follows that the principle of negative number is a negative.

To the fourth, the antecedent is denied. For "one" does not signify a perfection unless the privative division signifies an imperfection. Hence, just as relation does not formally signify a perfection simply speaking, neither does its unity; otherwise paternity and filiation in God would be at once imperfect, because not one. And just as substantial being (esse) signifies a perfection, so does its unity. "One" therefore abstracts from both perfection and imperfection. – To the first proof, however, drawn from Anselm's definition ⁵, it is said that the particle "better" is lacking here: for what is not good cannot be better. – To the second, however, it is said that that reduction is not proper to perfections simply speaking, but is common also to general negatives. Hence the reduction is made to the supremely immutable, the supremely immaterial, etc. – Although it could also fittingly be said that, as is stated in IV⁶ and VII Metaphysics⁷, the analogate investigated in the absolute is sought for the first: and by this, the first one, which is a substantial one, is a perfection simply speaking, and is reduced to the supremely one. But from this nothing follows against our intent: because that perfection belongs to it by reason of the substance it implies.

VI. In response to the first objection, note that the Scotists inveigh against the argument of Averroes, in IV Metaphysics, commentary III, against Avicenna, which St. Thomas used. For they say⁸ that it is a sophism of Figure of Speech, because the whereby is changed into the what: for that whereby a thing is one is one as whereby, not as what. And therefore no process to infinity follows; just as none follows from white and whiteness.

But this objection is very crude. First, because it is established that in the transcendentals the concrete is truly predicated of the abstract (for entity is a being, and unity is one); and by this quo is not changed into quod; rather, reason itself uses that same quo in both ways, namely as quo and as quod. And therefore it concludes excellently: neither is it similar in the case of white and whiteness, because whiteness is not white. – Second, because if "one" added another nature above being, say above man or lion, then by the same reasoning whereby this proposition is true, the nature of man is one, the same will be true: the nature of unity is one; for every nature is one. Nor does the adjacency of the nature excuse this, namely because the nature of unity always inheres in another, and on that account is a quo; for it is common to every nature, whether subsistent or non-subsistent, to be one, as is evident in accidents. Therefore the argument stands in its full force.

But concerning the one, which is the principle of number and what sort of accident it is, this is not the business of the present work; it will be a special question.

VII. In response to the second objection, note carefully: since this argument causes the learned to waver, because they do not penetrate this response. Know that the response of the text rests on those words, being is divided into one and many, as into one simply and many in a certain respect: and the simply and in a certain respect do not modify the one or the many, but modify the is divided. And the sense is that being is divided simply into one, and in a certain respect into many: that is, the one is contained under being simply, but the many in a certain respect. Hence this is immediately proved in the text: for even the, he says, many are not contained under being except as participating in one. And since it is established that the nature of such a division is such that the member taken simply equals the thing divided taken absolutely (and rightly so, because a member in a certain respect does not partake of the thing divided except in a certain respect); therefore the response stands very well, both that the one is convertible with being, and yet is a member of the division. An example of this is if man is distinguished into man in act and man in potency: and likewise a house into a house in act and in potency, etc. – The remaining points set down in this response are for the perfection of the doctrine, and for the explanation of the intended meaning: since both the one, whether simply or in a certain respect, and the many, whether simply or in a certain respect, participate in one.