If at first the idea is not absurd, then there is no hope for it.

A man has to work so hard so that something of his personality stays alive. A tomcat has it so easy, he has only to spray and his presence is there for years on rainy days.

It would be a sad situation if the bag was better than the meat wrapped in it.

The finest emotion of which we are capable is the mystic emotion. Herein lies the germ of all art and all true science. Anyone to whom this feeling is alien, who is no longer capable of wonderment and lives in a state of fear is a dead man.

I was just more stubborn and more passionate than most about physics.

What distinguishes the language of science from language as we ordinarily understand the word? ... What science strives for is an utmost acuteness and clarity of concepts as regards their mutual relation and their correspondence to sensory data.

Do you really believe that the moon isn’t there when nobody looks?