Commentaria in Primam Partem Summae Theologiae

A clear title. – In the body there are two parts: first, he answers the question; second, he assigns the reason for the several definitions of truth, there: And according to this, truth ¹.

II. As to the first, the responsive conclusion to the question is: Truth is principally in the intellect, secondarily in things, in relation to the intellect on which they depend.

This conclusion has three parts. And as to the first, it is proved as follows: The true is the term of the intellect; therefore it is in the intellect. – The antecedent is explained by the proportional agreement between the true and the good: for just as the good signifies that toward which appetite tends, so the true signifies that toward which the intellect tends. The consequence, however, is proved from the difference between appetite and cognition, from Book VI of the Metaphysics ²: because the former is completed outside, the latter within.

As for the second part, namely that truth is in things secondarily, it is proved there: But as the good. Truth is in the intellect insofar as it is conformed to the thing understood; therefore the ratio of truth is derived from the intellect to the thing understood; therefore the thing understood is called true insofar as it has an order to the intellect. – The antecedent is made clear from the proportional agreement between good and truth: for just as the good is in a thing as suitable to appetite, so truth is in the intellect, etc. Both consequences are likewise proved from the same root: the first, because from the good in a thing goodness is derived to appetite; the second also, because on this account appetite for the good is called good.

As to the third part, namely that from which it depends, it is proved there, The thing understood, however, in two ways: first, by reason; second, from the effects. The reason is this. A judgment about any thing is not made according to those features that belong to it accidentally, but essentially: therefore each thing is said to be true absolutely, in relation to the intellect on which it depends. The antecedent is evident. The consequence is proved from the difference between a thing's order to an intellect that is causative and one that is merely cognitive: namely, that to the latter it has an accidental order, but to the former an essential one; which is illustrated by the example of a house with respect to the craftsman and to one who is not a craftsman. – The effects, moreover, that bear witness to these truths are artificial things and natural things. For artificial things, both mechanical ones, such as a house, and liberal ones, such as speech, are true absolutely if they conform to their arts. Natural things too are true absolutely if they accord with the maker, whom we take to be the first intellect.

III. Concerning the foregoing, two propositions are to be noted. The first is, truth is that toward which the intellect tends, as the good, etc.: for this will be discussed below, art. 3, ad tertium ³. The second is, cognition is according as the thing known is in the knower, but appetite according to an inclination toward the thing: and this will be defended in qu. LXXXII, art. 3 ⁴, where the will is compared with the intellect.

IV. As regards according to ⁵, the reason for the six definitions of truth is given: three pertain to truth in things, two to truth in the intellect, and one to truth in both. All is clear.