Courage is never to let your actions be influenced by your fears.

[My father] loved me tenderly and shyly from a distance, and later on took a naive pride in seeing my name in print.

A writer's ambition should be to trade a hundred contemporary readers for ten readers in ten years' time and for one reader in a hundred years' time.

The principle mark of genius is not perfection but originality, the opening of new frontiers.

Courage is never to let your actions be influenced by your fears.

The moment of truth, the sudden emergence of a new insight, is an act of intuition. Such intuitions give the appearance of miraculous flushes, or short-circuits of reasoning. In fact they may be likened to an immersed chain, of which only the beginning and the end are visible above the surface of consciousness. The diver vanishes at one end of the chain and comes up at the other end, guided by invisible links.

In my youth I regarded the universe as an open book, printed in the language of equations, whereas now it appears to me as a text written in invisible ink, of which in our rare moments of grace we are able to decipher a small segment.