To me the most interesting thing about man is that he is an animal who practices art and science and in every known society practices both together.

Whether our work is art or science or the daily work of society, it is only the form in which we explore our experience which is different.

Beyond all our actions stands the larger shadow: How are we to choose between what we have been taught to think right and something else which manifestly succeeds?

Knowledge is not a loose-leaf notebook of facts. Above all, it is a responsibility for the integrity of what we are, primarily of what we are as ethical creatures.

The air in a man's lungs 10,000,000,000, 000,000,000,000 atoms, so that sooner or later every one of us breathes an atom that has been breathed before by anyone you can think of who has ever lived - Michelangelo or George Washington or Moses.

The paradox of knowledge is not confined to the small, atomic scale; on the contrary, it is as cogent on the scale of man, and even of the stars.

That series of inventions by which man from age to age has remade his environment is a different kind of evolution -- not biological, but cultural evolution . . . "The Ascent of Man.