We still do not know one thousandth of one percent of what nature has revealed to us.

Occurrences in this domain are beyond the reach of exact prediction because of the variety of factors in operation, not because of any lack of order in nature.

It stands to the everlasting credit of science that by acting on the human mind it has overcome man's insecurity before himself and before nature.

Nationalism is an infantile disease. It is the measles of mankind.

Heroism on command, senseless violence, and all the loathsome nonsense that goes by the name of patriotism - how passionately I hate them!

Peace cannot be kept by force it can only be achieved by understanding.

I am not only a pacifist but a militant pacifist. I am willing to fight for peace. Nothing will end war unless the people themselves refuse to go to war.

Pure mathematics is, in its way, the poetry of logical ideas.

Politics is for the present, but an equation is for eternity.

The gift of fantasy has meant more to me than my talent for absorbing positive knowledge.