Great art is indefinable but that's all right; it exists anyway.

America My Country: last nation on earth to abolish human slavery; first of all nations to drop the nuclear bomb on our fellow human beings.

Has joy any survival value in the operations of evolution? I suspect that it does; I suspect that the morose and fearful are doomed to quick extinction. Where there is no joy there can be no courage; and without courage all other virtues are useless.

Science transcends mere politics. As recent history demonstrates, scientists are as willing to work for a Tojo, a Hitler, or a Stalin as for the free nations of the West.

The world is what it is, no less and no more, and therein lies its entire and sufficient meaning.

The industrial corporation is the natural enemy of nature.

I would not sacrifice a single living mesquite tree for any book ever written. One square mile of living desert is worth a hundred 'great books' - and one brave deed is worth a thousand.