The difference between stupidity and genius is that genius has its limits.

We are here for the sake of others

No one must think that Newton’s great creation can be overthrown in any real sense by this [Theory of Relativity] or by any other theory. His clear and wide ideas will for ever retain their significance as the foundation on which our modern conceptions of physics have been built.

Relativity applies to physics, not ethics.

I think 99 times and find nothing. I stop thinking, swim in the silence, and the truth comes to me.

The formulation of the problem is often more essential than its solution, which may be merely a matter of mathematical or experimental skill.

Never let yourself be seduced by any problem, no matter how difficult.