The truth of a theory is in your mind, not in your eyes.

It is just as important to make knowledge live and keep it alive as to solve specific problems.

We can understand almost anything, but we can't understand how we understand.

The goal of pacifism is possible only though a supranational organization. To stand unconditionally for this cause is the criterion of true pacifism.

Only six men in the world know about relativity. I am not one of them. When I ask them to explain, they confused me.

If I had my life to live over again, I would elect to be a trader of goods rather than a student of science. I think barter is a noble thing.

Politics is far more complicated than physics.