Reply Obj. 2: The true and being are convertible terms. Hence just as being is not generated nor corrupted of itself, but accidentally, in so far as this being or that is corrupted or generated, as is said in Phys. i, so does truth change, not so as that no truth remains, but because that truth does not remain which was before.
Reply Obj. 3: A proposition not only has truth, as other things are said to have it, in so far, that is, as they correspond to that which is the design of the divine intellect concerning them; but it is said to have truth in a special way, in so far as it indicates the truth of the intellect, which consists in the conformity of the intellect with a thing. When this disappears, the truth of an opinion changes, and consequently the truth of the proposition. So therefore this proposition, "Socrates sits," is true, as long as he is sitting, both with the truth of the thing, in so far as the expression is significative, and with the truth of signification, in so far as it signifies a true opinion. When Socrates rises, the first truth remains, but the second is changed.
Reply Obj. 4: The sitting of Socrates, which is the cause of the truth of the proposition, "Socrates sits," has not the same meaning when Socrates sits, after he sits, and before he sits. Hence the truth which results, varies, and is variously signified by these propositions concerning present, past, or future. Thus it does not follow, though one of the three propositions is true, that the same truth remains invariable. _______________________
QUESTION 17
CONCERNING FALSITY
(In Four Articles)
We next consider falsity. About this four points of inquiry arise:
(1) Whether falsity exists in things?
(2) Whether it exists in the sense?
(3) Whether it exists in the intellect?
(4) Concerning the opposition of the true and the false. _______________________