Full Idea
What the mind takes in is not some material element of the agent, but a likeness of the agent actualising some potential the patient already has. This, for example, is the way our seeing takes in the colour of a coloured body.
Clarification
Agents are viewed, patients do the viewing
Gist of Idea
Minds take in a likeness of things, which activates an awaiting potential
Source
Thomas Aquinas (Quodlibeta [1267], 8.2.1)
Book Reference
McDermott,Timothy: 'Aquinas: how to read' [Granta 2007], p.8
A Reaction
This is exactly right. Descartes agreed. It works for colour, but not (obviously) for cheese graters.
Related Idea
Idea 3631 A blind man may still contain the idea of colour [Descartes]