Truth is the product of the recognition (i.e., identification) of the facts of
reality. Man identifies and integrates the facts of reality by means of
concepts. He retains concepts in his mind by means of definitions. He organizes
concepts into propositions—and the truth or falsehood of his propositions
rests, not only on their relation to the facts he asserts, but also on the
truth or falsehood of the definitions of the concepts he uses to assert them,
which rests on the truth or falsehood of his designations of essential
characteristics.