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.

All those formal systems, in mathematics and physics and the philosophy of science, which claim to give foundations for certain truth are surely mistaken. I am tempted to say that we do not look for truth, but for knowledge. But I dislike this form of words, for two reasons. First of all, we do look for truth, however we define it, it is what we find that is knowledge. And second, what we fail to find is not truth, but certainty; the nature of truth is exactly the knowledge that we do find.

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?

Revolutions are not made by fate but by men.

The basis for poetry and scientific discovery is the ability to comprehend the unlike in the like and the like in the unlike.

The discoveries of science, the works of art are explorations - more, are explosions, of a hidden likeness. The discoverer or artist presents in them two aspects of nature and fuses them into one. This is the act of creation, in which an original thought is born, and it is the same act in original science and original art.

I set out to show that there exists single creative activity,which is displayed alike in the arts and in the sciences.It is wrong to think of science as a mechanical record of facts, and it is wrong to think of the arts as remote and private fancies. What makes each human, what makes them universal, is the stamp of the creative mind.