Happiness is the perfection of the soul on the part of the intellect, in respect of which the soul transcends the organs of the body
 Thomas Aquinas, Summa Theologica (1274). copy citation

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Author Thomas Aquinas
Source Summa Theologica
Topic perfection happiness
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

“answers "that they cannot see the Unchangeable Substance, as the blessed angels see It; either for some other more hidden reason, or because they have a natural desire to rule the body." Reply Obj. 1: Happiness is the perfection of the soul on the part of the intellect, in respect of which the soul transcends the organs of the body; but not according as the soul is the natural form of the body. Wherefore the soul retains that natural perfection in respect of which happiness is due to it, though it does not retain that natural perfection in respect of which it is the form of the body.” source