There's life all over this universe, but the only life in the solar system is on earth, and in the whole universe we are the only men.

Nuclear weapons offer us nothing but a balance of terror, and a balance of terror is still terror.

One has only to contemplate the magnitude of this task to concede that the spontaneous generation of a living organism is impossible. Yet here we are-as a result, I believe, of spontaneous generation.

I tell my students to try early in life to find an unattainable objective.

A scientist should be the happiest of men.

If the germ plasm wants to swim in the ocean, it makes itself a fish; if the germ plasm wants to fly in the air, it makes itself a bird. If it wants to go to Harvard, it makes itself a man. The strangest thing of all is that the germ plasm that we carry around within us has done all those things. There was a time, hundreds of millions of years ago, when it was making fish. Then ... amphibia ... reptiles ... mammals, and now it's making men.

We are living in a world in which all wars are wars of defense.