Even as a youngster, though, I could not bring myself to believe that if knowledge presented danger, the solution was ignorance.

Creationists make it sound as though a 'theory' is something you dreamt up after being drunk all night.

A fire-eater must eat fire even if he has to kindle it himself.

I do not fear computers. I fear the lack of them.

During the century after Newton, it was still possible for a man of unusual attainments to master all fields of scientific knowledge. But by 1800, this had become entirely impracticable.

The human brain, then, is the most complicated organization of matter that we know.

Nothing has to be true, but everything has to sound true.