Reply Obj. 3: Unchangeable persistence may belong to a virtue in two ways. First, on account of the intended end that is proper to that virtue; and thus to persist in good for a long time until the end, belongs to a special virtue called perseverance, which intends this as its special end.
 Thomas Aquinas, Summa Theologica (1274). copy citation

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Author Thomas Aquinas
Source Summa Theologica
Topic perseverance persistence
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

“Wherefore as regards these which are the principal virtues, the act of perseverance is not accomplished until the end of life. It is in this sense that Augustine speaks of perseverance as denoting the consummate act of perseverance.
Reply Obj. 3: Unchangeable persistence may belong to a virtue in two ways. First, on account of the intended end that is proper to that virtue; and thus to persist in good for a long time until the end, belongs to a special virtue called perseverance, which intends this as its special end. Secondly, by reason of the relation of the habit to its subject: and thus unchangeable persistence is consequent upon every virtue, inasmuch as virtue is a "quality difficult to change." _______________________
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