Thinking is hard work; that's why so few do it.

In my opinion there is no other salvation for civilization and even for the human race than the creation of a world government with security on the basis of law. As long as there are sovereign states with their separate armaments and armament secrets, new world wars cannot be avoided.

I have become rather like King Midas, except that everything turns not into gold but into a circus.

We cannot get to where we dream of being tomorrow unless we change our thinking today.

Nature shows us only the tail of the lion. But there is no doubt in my mind that the lion belongs with it even if he cannot reveal himself to the eye all at once because of his huge dimension.

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 you cannot explain it simply, you do not understand it enough.