Hence when a man esteems the good he has received of another as though he had it of himself, the result is that his appetite is borne towards his own excellence immoderately.
 Thomas Aquinas, Summa Theologica (1274). copy citation

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Author Thomas Aquinas
Source Summa Theologica
Topic self-esteem excellence
Date 1274
Language English
Reference
Note Translated by Fathers of the English Dominican Province
Weblink http://www.gutenberg.org/cache/epub/18755/pg18755-images.html

Context

“and thus we have the third species of pride, namely "boasting of having what one has not." Secondly, it may be considered with regard to its cause, in so far as to have a thing of oneself is more excellent than to have it of another. Hence when a man esteems the good he has received of another as though he had it of himself, the result is that his appetite is borne towards his own excellence immoderately. Now one is cause of one's own good in two ways, efficiently and meritoriously: and thus we have the first two species of pride, namely "when a man thinks he has from himself that which he has from God,"” source