The virtue which is called "truth" is not truth in general, but a certain kind of truth according to which man shows himself in deed and word as he really is.
 Thomas Aquinas, Summa Theologica (1274). copy citation

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Author Thomas Aquinas
Source Summa Theologica
Topic virtue truth
Date 1274
Language English
Reference
Note Translated by Fathers of the English Dominican Province
Weblink http://www.gutenberg.org/cache/epub/17611/pg17611-images.html

Context

“secondly, it apprehends that it understands being; and thirdly, it apprehends that it desires being. Hence the idea of being is first, that of truth second, and the idea of good third, though good is in things. Reply Obj. 3: The virtue which is called "truth" is not truth in general, but a certain kind of truth according to which man shows himself in deed and word as he really is. But truth as applied to "life" is used in a particular sense, inasmuch as a man fulfills in his life that to which he is ordained by the divine intellect, as it has been said that truth exists in other things” source