People like you and I, though mortal of course like everyone else, do not grow old no matter how long we live.

Weakness of attitude becomes weakness of character.

It is only to the individual that a soul is given.

With all my heart I believe that the world's present system of sovereign nations can only lead to barbarism, war and inhumanity, and that only world law can assure progress towards a civilized peaceful community.

For scientific endeavor is a natural whole the parts of which mutually support one another in a way which, to be sure, no one can anticipate.

Human beings are not condemned, because of their biological constitution, to annihilate each other or to be at the mercy of a cruel, self-inflicted fate.

I don't teach my students, I provide the circumstances in which they can learn.