Man usually avoids attributing cleverness to somebody else unless it is an enemy.

Except in mathematics, the shortest distance between point A and point B is seldom a straight line. I don't believe in mathematics.

My sailing system set sail, make it fast, no thoughts of energy or velocity, loll back, let boat drift.

The real problem is in the hearts and minds of men. It is not a problem of physics but of ethics. It is easier to denature plutonium than to denature the evil spirit of man.

I am exclusively occupied with the problem of gravitation and hope with the help of a local mathematician friend [Marcel Grossman] to overcome all the difficulties. One thing is certain, however, that never in life have I been quite so tormented. A great respect for mathematics has been instilled within me, the subtler aspects of which, in my stupidity, I regarded until now as pure luxury.

What you can't imagine, you can't discover.

The last thing to collapse is the surface.