From the moment of birth we are immersed in action, and can only fitfully guide it by taking thought.

Necessity is the mother of invention is a silly proverb. Necessity is the mother of futile dodges is much nearer the truth.

A clash of doctrines is not a disaster--it is an opportunity.

Everything of importance has been said before by somebody who did not discover it.

I have suffered a great deal from writers who have quoted this or that sentence of mine either out of its context or in juxtaposition to some incongruous matter which quite distorted my meaning , or destroyed it altogether.

Seek simplicity, and distrust it.

The future belongs to those who can rise above the confines of the earth.

We think in generalities, but we live in detail.

I will not go so far as to say that to construct a history of thought without profound study of the mathematical ideas of successive epochs is like omitting Hamlet from the play which is named after him. . . But it is certainly analogous to cutting out the part of Ophelia. This simile is singularly exact. For Ophelia is quite essential to the play, she is very charming-- and a little mad.

Nature gets credit which should in truth be reserved for ourselves: the rose for its scent, the nightingale for its song; and the sun for its radiance. The poets are entirely mistaken. They should address their lyrics to themselves and should turn them into odes of self-congratulation on the excellence of the human mind.