We gain our ends only with the laws of nature; we control her only by understanding her laws.

The values by which we are to survive are not rules for just and unjust conduct, but are those deeper illuminations in whose light justice and injustice, good and evil, means and ends are seen in fearful sharpness of outline.

When Coleridge tried to define beauty, he returned always to one deep thought; beauty, he said, is unity in variety! Science is nothing else than the search to discover unity in the wild variety of nature,-or, more exactly, in the variety of our experience. Poetry, painting, the arts are the same search, in Coleridge's phrase, for unity in variety.

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.

We have to understand that the world can only be grasped by action, not by contemplation. The hand is more important than the eye ... The hand is the cutting edge of the mind.

In the moment of appreciation we live again the moment when the creator saw and held the hidden likeness.

The symbol and the metaphor are as necessary to science as to poetry.