The intellect alone apprehends the essences of things.
 Thomas Aquinas, Summa Theologica (1274). copy citation

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Author Thomas Aquinas
Source Summa Theologica
Topic intellect essence
Date 1274
Language English
Reference
Note Translated by Fathers of the English Dominican Province
Weblink http://www.gutenberg.org/cache/epub/17611/pg17611-images.html

Context

“And thus the intelligible species which are in the intellect of an angel are perfections and acts in regard to that intellect. Reply Obj. 2: Sense does not apprehend the essences of things, but only their outward accidents. In like manner neither does the imagination; for it apprehends only the images of bodies. The intellect alone apprehends the essences of things. Hence it is said (De Anima iii, text. 26) that the object of the intellect is "what a thing is," regarding which it does not err; as neither does sense regarding its proper sensible object. So therefore the essences of material things are in the intellect of man and angels, as the thing understood is in him who understands, and not according to their real natures.” source