The rules of logic are to mathematics what those of structure are to architecture.

So far I have been speaking of theoretical science, which is an attempt to understand the world. Practical science, which is an attempt to change the world, has been important from the first, and has continually increased in importance, until it has almost ousted theoretical science from men's thoughts.

Truth is for the gods; from our human point of view, it is an ideal, towards which we can approximate, but which we cannot hope to reach.

It is a waste of energy to be angry with a man who behaves badly, just as it is to be angry with a car that won't go.

I believe myself that romantic love is the source of the most intense delights that life has to offer. In the relation of a man and woman who love each other with passion and imagination and tenderness, there is something of inestimable value, to be ignorant of which is a great misfortune to any human being.

Orthodoxy is the death of intelligence.

The first dogma which I came to disbelieve was that of free will. It seemed to me that all notions of matter were determined by the laws of dynamics and could not therefore be influenced by human wills.