A man may judge in one way by inclination, as whoever has the habit of a virtue judges rightly of what concerns that virtue by his very inclination towards it. Hence it is the virtuous man, as we read, who is the measure and rule of human acts. In another way, by knowledge, just as a man learned in moral science might be able to judge rightly about virtuous acts, though he had not the virtue.
 Thomas Aquinas, Summa Theologica (1274). copy citation

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Author Thomas Aquinas
Source Summa Theologica
Topic science virtue
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

“"Destroying counsels and every height that exalteth itself against the knowledge of God" (2 Cor. 10:4, 5) . Reply Obj. 3: Since judgment appertains to wisdom, the twofold manner of judging produces a twofold wisdom. A man may judge in one way by inclination, as whoever has the habit of a virtue judges rightly of what concerns that virtue by his very inclination towards it. Hence it is the virtuous man, as we read, who is the measure and rule of human acts. In another way, by knowledge, just as a man learned in moral science might be able to judge rightly about virtuous acts, though he had not the virtue. The first manner of judging divine things belongs to that wisdom which is set down among the gifts of the Holy Ghost: "The spiritual man judgeth all things" (1 Cor. 2:15) . And Dionysius says (Div. Nom.” source