Wherefore moderated sorrow for an object which ought to make us sorrowful, is a mark of virtue; as also the Philosopher says (Ethic. ii, 6, 7) .
 Thomas Aquinas, Summa Theologica (1274). copy citation

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Author Thomas Aquinas
Source Summa Theologica
Topic virtue sorrow
Date 1274
Language English
Reference
Note Translated by Fathers of the English Dominican Province
Weblink http://www.gutenberg.org/cache/epub/17897/pg17897-images.html

Context

“Wherefore the sensitive appetite follows reason's rejection by sorrowing for that evil; yet moderately, according as reason dictates. Now it pertains to virtue that the sensitive appetite be conformed to reason, as stated above (A. 1, ad 2). Wherefore moderated sorrow for an object which ought to make us sorrowful, is a mark of virtue; as also the Philosopher says (Ethic. ii, 6, 7) . Moreover, this proves useful for avoiding evil: since, just as good is more readily sought for the sake of pleasure, so is evil more undauntedly shunned on account of sorrow.
Accordingly we must allow that sorrow for things pertaining to virtue is incompatible with virtue: since virtue rejoices in its own.” source