The truth of life is the truth whereby a thing is true, not whereby a person says what is true.
 Thomas Aquinas, Summa Theologica (1274). copy citation

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Author Thomas Aquinas
Source Summa Theologica
Topic truth life
Date 1274
Language English
Reference
Note Translated by Fathers of the English Dominican Province
Weblink http://www.gutenberg.org/cache/epub/18755/pg18755-images.html

Context

“although it may belong to other virtues consequently and beside his principal intention. For the brave man intends to act bravely: and that he shows his fortitude by acting bravely is a consequence beside his principal intention. Reply Obj. 3: The truth of life is the truth whereby a thing is true, not whereby a person says what is true. Life like anything else is said to be true, from the fact that it attains its rule and measure, namely, the divine law; since rectitude of life depends on conformity to that law. This truth or rectitude is common to every virtue.” source