Youth is life as yet unblemished by much tragedy, but hardly by TV.

Dogmatism is the anti-Christ of learning.

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. That would be claiming too much. 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.

It is the business of the future to be dangerous; and it is among the merits of science that it equips the future for its duties.

To come very near to a true theory, and to grasp its precise application, are two different things, as the history of science teaches us. Everything of importance has been said before by someone who did not discover it.

I put forward as a general definition of civilization, that a civilized society is exhibiting the five qualities of Truth, Beauty, Adventure, Art, Peace.

Without adventure all civilization is full of decay. Adventure rarely reaches its predetermined end. Columbus never reached China.