There are no whole truths: All truths are half-truths.

Life is complex in its expression, involving more than percipience, namely desire, emotion, will, and feeling.

I regret that it has been necessary for me in this lecture to administer a large dose of four-dimensional geometry. I do not apologize, because I am really not responsible for the fact that nature in its most fundamental aspect is four-dimensional. Things are what they are.

I consider Christian theology to be one of the great disasters of the human race.

The worst that happened to men of science was that Galileo suffered an honorable detention and a mild reproof, before dying peacefully in his bed.

The study of mathematics is apt to commence in disappointment.

The main importance of Francis Bacon's influence does not lie in any peculiar theory of inductive reasoning which he happened to express, but in the revolt against second-hand information of which he was a leader.