For the intellect is false if it understands an object otherwise than as it really is.
 Thomas Aquinas, Summa Theologica (1274). copy citation

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Author Thomas Aquinas
Source Summa Theologica
Topic understanding intellect
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

“Whether Our Intellect Understands Corporeal and Material Things by Abstraction from Phantasms? Objection 1: It would seem that our intellect does not understand corporeal and material things by abstraction from the phantasms. For the intellect is false if it understands an object otherwise than as it really is. Now the forms of material things do not exist as abstracted from the particular things represented by the phantasms. Therefore, if we understand material things by abstraction of the species from the phantasm, there will be error in the intellect.” source