If you have a good scientific imagination, you can think of all sorts of things that might be true, and that’s the essence of science. You first think of something that might be true — then you look to see if it is, and generally it isn’t.

Bertrand Russell (1872–1970) English mathematician and philosopher

Interview by Woodrow Wyatt, BBC TV (1959)

Collected in Bertrand Russell's BBC Interviews (1959) [UK] and Bertrand Russell Speaks His Mind (1960) [US].