I find it difficult to believe that I belong to such an idiotic, rotten species - the species that actually boasts of its freedom of will, heroism on command, senseless violence, and all of the loathsome nonsense that goes by the name of patriotism.

You must be aware that most men (and also not only a few women) are by nature not monogamous. This nature makes itself even more forceful when tradition and circumstance stand in an individual's way.

It would be better if you began to teach others only after you yourself have learned something.

Joy in looking and comprehending is nature's most beautiful gift.

I have tried 99 times and have failed, but on the 100th time came success.

The words of language, as they are written or spoken, do not seem to play any role in my mechanism of thought. The physical entities which seem to serve as elements in thought are certain signs and more or less clear images.

This change in the conception of reality is the most profound and the most fruitful that physics has experienced since the time of Newton. Refering to James Clerk Maxwell's contributions to physics.