Commentaria in Primam Partem Summae Theologiae

In the title: to come into the composition of another requires four conditions. The first is real distinction from that other: for there is no composition of a thing with itself. The second is real conjunction with it: for composition does not arise from conjunction according to reason alone. The third is that the conjunction be according to its esse: for composition does not arise from merely real conjunction according to position, or any other extrinsic respect. The fourth is that one be the act of the other: or of some third thing actualized by both, if the composition is accidental, as between white and sweet. For if two things are joined even according to esse, yet not in the relation of act and potency, then, as we have said, there is never composition: as is evident both in the case of the divine persons and of the divine Word incarnate (for in such cases the ratio of act and potency is absent). – To ask, therefore, whether God comes into the composition of other things is to ask whether he can be conjoined with another thing according to esse, in the relation of act or potency.

II. In the body there are two points: first, the errors are set forth; second, the question is answered. – As to the first, there are three errors: the first is that of the Sabaeans, from Book XII of the Metaphysics, in Averroes's forty-first commentary ¹; the second is that of the Almaricians; the third is that of David of Dinant. And this is evident.

III. As to the second point, the responsive conclusion to the question, and the destructive one against these errors, is negative: God cannot enter into the composition of anything.

It is proved in three ways. First. God is the first efficient cause; therefore he cannot be the form or matter of any composite. – The antecedent is evident. The consequence is proved with respect to form: an agent and the form of its effect do not coincide in one and the same thing numerically; therefore if, etc. With respect to matter, however: agent and matter do not coincide in one and the same species, because the former is in act, the latter in potency; therefore if, etc.

IV. Concerning this argument a doubt arises. For the proof of the consequence does not seem to the point: from the fact that the efficient cause does not coincide with the form or matter of its effect, nothing else follows except that God, because he is the efficient cause, is not the form or matter of his own effect; but it does not follow that he is absolutely not the form of any composite. To this it is briefly answered that, since the being of a composite entails being an effect (because every composite is made, as is clear in the preceding article); and being an effect entails being the effect of the first efficient cause, as is evident: therefore, from first to last, the being of a composite is the being of an effect of the first efficient cause. And for this reason, supposing this as established, the argument of the text most fittingly draws the consequence: if God is the first efficient cause, he is not the form or matter of any composite: since he would be the form or matter of his own effect, which is impossible, because the agent does not coincide, etc.

V. Second argument. God is the first agent through himself; therefore he is not a part of anything. – The inference is proved. No component is an agent first and of itself; therefore if, etc.

Note here that this text must be interpreted cautiously. For it does not affirm that the composite acts per se first, which was denied above, in article 2; rather it affirms a comparative claim, namely that to act per se first belongs more to the composite than to the component, because the former is that which acts, while the latter is that by which. Yet alongside this it stands that, absolutely speaking, neither the component nor the composite can be the per se first agent, as has been said.

VI. The third argument is: God is the first being (ens); therefore He cannot be a part, not even a primary one, such as matter or form. – The consequence is proved: as regards matter, indeed, because potency is posterior to act; as regards form, however, because participated act is posterior to act by essence, etc.