Every defect causes a vice, but not every good is sufficient for the notion of virtue.
 Thomas Aquinas, Summa Theologica (1274). copy citation

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Author Thomas Aquinas
Source Summa Theologica
Topic vice virtue
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

“Nevertheless in so far as the vices opposed to other virtues are base and disgraceful, shamefacedness may also pertain to other virtues. Reply Obj. 3: Shamefacedness fosters honesty, by removing that which is contrary thereto, but not so as to attain to the perfection of honesty. Reply Obj. 4: Every defect causes a vice, but not every good is sufficient for the notion of virtue. Consequently it does not follow that whatever is directly opposed to vice is a virtue, although every vice is opposed to a virtue, as regards its origin. Hence shamelessness, in so far as it results from excessive love of disgraceful things, is opposed to temperance.” source