Science, like art, is not a copy of nature but a re-creation of her.

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

Dream or nightmare, we have to live our experience as it is, and we have to live it awake. We live in a world which is penetrated through and through by science and which is both whole and real. We cannot turn it into a game simple by taking sides.

Every animal leaves traces of what it was; man alone leaves traces of what he created.

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.

The largest single step in the ascent of man is the change from nomad to village agriculture.

The world can only be grasped by action, not by contemplation.