Declining from evil is a more imperfect act, and a secondary part of that virtue.
 Thomas Aquinas, Summa Theologica (1274). copy citation

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Author Thomas Aquinas
Source Summa Theologica
Topic evil 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

“shows. This is meritorious; especially when a person resists against an instigation to do evil. Reply Obj. 3: Doing good is the completive act of justice, and the principal part, so to speak, thereof. Declining from evil is a more imperfect act, and a secondary part of that virtue. Hence it is a material part, so to speak, thereof, and a necessary condition of the formal and completive part. _______________________ SECOND ARTICLE [II-II, Q. 79, Art. 2] Whether Transgression Is a Special Sin?” source