Full Idea
Were I to look out of my window and observe men crossing the square, I would ordinarily say that I see the men themselves. But what do I see but hats and clothes, which could conceal automata? Yet I judge them to be men.
Gist of Idea
We don't 'see' men in heavy clothes, we judge them to be men
Source
René Descartes (Meditations [1641], §2.32)
Book Reference
Descartes,René: 'Discourse on Method/The Meditations', ed/tr. Sutcliffe,F.E. [Penguin 1968], p.110