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.

The private motives of scientists are not the trend of science. The trend of science is made by the needs of society: navigation before the eighteenth century, manufacture thereafter; and in our age I believe the liberation of personality. Whatever the part which scientists like to act, or for that matter which painters like to dress, science shares the aims of our society just as art does.

You will die but the carbon will not; its career does not end with you. It will return to the soil, and there a plant may take it up again in time, sending it once more on a cycle of plant and animal life.

It is not the business of science to inherit the earth, but to inherit the moral imagination; because without that, man and beliefs and science will perish together.

Certainty ends inquiry.

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.