Astronomy is not the apex of science or of invention. But it is a test of the cast of temperament and mind that underlies a culture.

But nature - that is, biological evolution - has not fitted man to any specific environment. On the contrary, ... he has a rather crude survival kit; and yet -this is the paradox of the human condition - one that fits him to all environments. Among the multitude of animals which scamper, fly, burrow and swim around us, man is the only one who is not locked into his environment. His imagination, his reason, his emotional subtlety and toughness, make it possible for him not to accept the environment but to change it.

It is important that students bring a certain ragamuffin, barefoot irreverence to their studies; they are not here to worship what is known, but to question it.

The most remarkable discovery ever made by scientists is science itself. The discovery must be compared in importance with the invention of cave-painting and of writing.

I grew up to be indifferent to the distinction between literature and science, which in my teens were simply two languages for experience that I learned together.

Man is unique not because he does science, and his is unique not because he does art, but because science and art equally are expressions of his marvelous plasticity of mind.

The preoccupation with the choice of a mate both by male and female I regard as a continuing echo of the major selective force by which we have evolved.