As far as the laws of mathematics refer to reality, they are not certain, and as far as they are certain, they do not refer to reality.

Gravitation cannot be held responsible for people falling in love. How on earth can you explain in terms of chemistry and physics so important a biological phenomenon as first love? Put your hand on a stove for a minute and it seems like an hour. Sit with that special girl for an hour and it seems like a minute. That’s relativity.

Pure mathematics is, in its way, the poetry of logical ideas. … [By seeking] logical beauty spiritual formulas are discovered necessary for the deeper penetration into the laws of nature.

A world government with powers adequate to guarantee security is not a remote ideal for the distant future. It is an urgent necessity if our civilization is to survive.

All means prove but blunt instruments, if they have not behind them a living spirit.

All these constructions and the laws connecting them can be arrived at by the principle of looking for the mathematically simplest concepts and the link between them.

America is a democracy and has no Hitler, but I am afraid for her future; there are hard times ahead for the American people, troubles will be coming from within and without. America cannot smile away their Negro problem nor Hiroshima and Nagasaki. There are cosmic laws.

As long as I have any choice in the matter, I shall live only in a country where civil liberty, tolerance and equality of all citizens before the law prevail.