Full Idea
Folk psychology is indispensable for driving a car, which would be terrifying if we didn't assume there were psychologically normal people behind the wheels.
Gist of Idea
You couldn't drive a car without folk psychology
Source
Daniel C. Dennett (works [1985]), quoted by Georges Rey - Contemporary Philosophy of Mind p.133 n35
Book Reference
Rey,Georges: 'Contemporary Philosophy of Mind' [Blackwell 1997], p.133
A Reaction
Nice example. If someone is approaching you from the front on your side of the road, should you assume that they are 'psychologically normal'? Does psychology imply behaviour, or vice versa?