If my theory of relativity is proven successful, Germany will claim me as a German and France will declare me a citizen of the world. Should my theory prove untrue, France will say that I am a German, and Germany will declare that I am a Jew.

Physical concepts are free creations of the human mind, and are not, however it may seem, uniquely determined by the external world.

If I could do it all again, I'd be a plumber.

Three great forces rule the world: stupidity, fear and greed.

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.

If I am right the Germans will say I was a German, and the French will say I was a Jew; If I am wrong the Germans will say I was a Jew and the French will say I was a German.

If the workers of this world, men and women, decide not to manufacture and transport ammunition, it would end war for all time. We must do that. Dedicate our lives to drying up the source of war; ammunition factories.