Full Idea
Knowing beings are differentiated from non-knowing beings by this: non-knowing beings have only their own reality, but knowing beings are capable of possessing also the reality of something else, ...a presence of the thing known produced by this thing.
Gist of Idea
A knowing being possesses a further reality, the 'presence' of the thing known
Source
Thomas Aquinas (Summa Theologicae [1265], Ia,q.Q14,art 1)
A Reaction
[Quoted by Ryan Meade in a talk at Pigotts] A famous and much discussed remark. Aquinas was a direct realist about perception, so this presence seems to be the thing itself, rather than a 'representation'.