abundant justice restrains anger, which is a less grievous sin than murder, which less abundant justice restrains.
 Thomas Aquinas, Summa Theologica (1274). copy citation

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Author Thomas Aquinas
Source Summa Theologica
Topic anger justice
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

“It would seem that the gravity of sins does not vary according to the excellence of the virtues to which they are opposed, so that, to wit, the graver sin is opposed to the greater virtue. For, according to Prov. 15:5, "In abundant justice there is the greatest strength." Now, as Our Lord says (Matt. 5:20, seqq.) abundant justice restrains anger, which is a less grievous sin than murder, which less abundant justice restrains. Therefore the least grievous sin is opposed to the greatest virtue. Obj. 2: Further, it is stated in Ethic. ii, 3 that "virtue is about the difficult and the good": whence it seems to follow that the greater virtue is about what is more difficult.” source