For the proper object of sorrow is one's own 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

“In accordance with this manner of speaking, the species of sorrow are reckoned by an application of the notion of sorrow to something foreign to it. This foreign matter may be taken on the part of the cause or the object, or of the effect. For the proper object of sorrow is one's own evil. Hence sorrow may be concerned for an object foreign to it either through one's being sorry for an evil that is not one's own; and thus we have pity which is sorrow for another's evil, considered, however, as one's own:” source