Consequently, a pleasure can be man's highest good, in the way above stated (Q. 34, A. 3) : whereas sorrow cannot be man's greatest evil.
 Thomas Aquinas, Summa Theologica (1274). copy citation

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Author Thomas Aquinas
Source Summa Theologica
Topic evil 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

“1: Pleasure and sorrow have two good points in common: namely, a true judgment concerning good and evil; and the right order of the will in approving of good and rejecting evil. Thus it is clear that in pain or sorrow there is a good, by the removal of which they become worse: and yet there is not an evil in every pleasure, by the removal of which the pleasure is better. Consequently, a pleasure can be man's highest good, in the way above stated (Q. 34, A. 3) : whereas sorrow cannot be man's greatest evil. Reply Obj. 2: The very fact of the will being opposed to evil is a good. And for this reason, sorrow or pain cannot be the greatest evil; because it has an admixture of good.
Reply Obj. 3: That which harms the better thing is worse than that which harms the worse.” source