Accordingly, concupiscence is a passion differing in species from both love and pleasure. But concupiscences of this or that pleasurable object differ in number.
 Thomas Aquinas, Summa Theologica (1274). copy citation

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Author Thomas Aquinas
Source Summa Theologica
Topic passion pleasure
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 object of sensible pleasure causes love, inasmuch as, so to speak, it attunes and conforms the appetite to itself; it causes concupiscence, inasmuch as, when absent, it draws the faculty to itself; and it causes pleasure, inasmuch as, when present, it makes the faculty to find rest in itself. Accordingly, concupiscence is a passion differing in species from both love and pleasure. But concupiscences of this or that pleasurable object differ in number. Reply Obj. 1: Pleasurable good is the object of concupiscence, not absolutely, but considered as absent: just as the sensible, considered as past, is the object of memory. For these particular conditions diversify the species of passions, and even of the powers of the sensitive part, which regards particular things.
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