t the species of
natural things did not proceed from any intellect, but were produced
by chance. But as they saw that truth implies relation to intellect,
they were compelled to base the truth of things on their relation to
our intellect. From this, conclusions result that are inadmissible,
and which the Philosopher refutes (Metaph. iv). Such, however, do not
follow, if we say that the truth of things consists in their relation
to the divine intellect.

Reply Obj. 3: Although the truth of our intellect is caused by the
thing, yet it is not necessary that truth should be there primarily,
any more than that health should be primarily in medicine, rather
than in the animal: for the virtue of medicine, and not its health,
is the cause of health, for here the agent is not univocal. In the
same way, the being of the thing, not its truth, is the cause of
truth in the intellect. Hence the Philosopher says that a thought or
a word is true "from the fact that a thing is, not because a thing is
true."
_______________________

SECOND ARTICLE [I, Q. 16, Art. 2]

Whether Truth Resides Only in the Intellect Composing and Dividing?

Objection 1: It seems that truth does not reside only in the intellect
composing and dividing. For the Philosopher says (De Anima iii) that
as the senses are always true as regards their proper sensible
objects, so is the intellect as regards "what a thing is." Now
composition and division are neither in the senses nor in the
intellect knowing "what a thing is." Therefore truth does not reside
only in the intellect composing and dividing.

Obj. 2: Further, Isaac says in his book _On Definitions_ that truth
is the equation of thought and thing. Now just as the intellect with
regard to complex things can be equated to things, so also with regard
to simple things; and this is true also of sense apprehending a thing
as it is. Therefore truth does not reside only in the intellect
composing and dividing.

_On the contrary,_ the Philosopher says (Metaph. vi) that with regard to
simple things and "what a thing is," truth is "found neither in the
intellect nor in things."

_I answer that,_ As stated before, truth resides, in its primary aspect,
in the intellect. Now since everything is true according as it has the
form proper to its nature, the intellect, in so far as it is knowing,
must be true, so far as it has the likeness of the thing known, this
being its form, as knowing. For this reason truth is def