If the intellect sees the difference or comparison between one thing and another, it knows both in relation to their difference or comparison
 Thomas Aquinas, Summa Theologica (1274). copy citation

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Author Thomas Aquinas
Source Summa Theologica
Topic comparison difference
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

“First, in a confused way, as existing in the whole, and thus they are known through the one form of the whole, and so are known together. In another way they are known distinctly: thus each is known by its species; and so they are not understood at the same time. Reply Obj. 4: If the intellect sees the difference or comparison between one thing and another, it knows both in relation to their difference or comparison; just, as we have said above (ad 3) , as it knows the parts in the whole. _______________________ FIFTH ARTICLE [I, Q. 85, Art. 5] Whether Our Intellect Understands by Composition and Division? Objection 1:” source