A description of cognitive agents

"INTELLIGENT beings are distinguished from non-intelligent beings in that the latter possess only their own form; whereas the intelligent being is naturally adapted to have also the form of some other thing; for the idea of the thing known is in the knower.

"Hence it is manifest that the nature of a non-intelligent being is more contracted and limited; whereas the nature of intelligent beings has a greater amplitude and extension; therefore the Philosopher [Aristotle] says (De Anima iii) that "the soul is in a sense all things."

"Now the contraction of the form comes from the matter. Hence, as we have said above (Q. 7, A. 1) forms according as they are the more immaterial, approach more nearly to a kind of infinity. Therefore it is clear that the immateriality of a thing is the reason why it is cognitive; and according to the mode of immateriality is the mode of knowledge. Hence it is said in De Anima ii that plants do not know, because they are wholly material. But sense is cognitive because it can receive images free from matter, and the intellect is still further cognitive, because it is more separated from matter and unmixed, as said in De Anima iii. Since therefore God is in the highest degree of immateriality as stated above (Q. 7, A. 1), it follows that He occupies the highest place in knowledge."

~St. Thomas Aquinas: Summa Theologica, I, Q, 14, A. 1.

Aristotle, by Enea Vico.
Engraving, 1546; British Museum, London.