“It is not always the magnitude of the differences observed between species that must determine specific distinctions, but the constant preservation of those differences in reproduction.”

The form follows the function.

It is not enough to discover and prove a useful truth previously unknown, but that it is necessary also to be able to propagate it and get it recognized.

All knowledge that is not the real product of observation, or of consequences deduced from observation, is entirely groundless and illusory.

Habits form a second nature.

What nature does in the course of long periods we do every day when we suddenly change the environment in which some species of living plant is situated.

All known living bodies are sharply divided into two special kingdoms, based upon the essential differences which distinguish animals from plants, and in spite of what has been said, I am convinced that these two kingdoms do not really merge into one another at any point.

It is not the organs-that is, the character and form of the animal’s bodily parts-that have given rise to its habits and particular structures. It is the habits and manner of life and the conditions in which its ancestors lived that have in the course of time fashioned its bodily form, its organs and qualities.

I have not tried to reproduce nature; I have represented it.

Light is a thing that cannot be reproduced, but must be represented by something else – by color.

To create is divine, to reproduce is human.

In just the same way the thousands of successive positions of a runner are contracted into one sole symbolic attitude, which our eye perceives, which art reproduces, and which becomes for everyone the image of a man who runs.

For the myth is the foundation of life; it is the timeless schema, the pious formula into which life flows when it reproduces its traits out of the unconscious.

People come up to me… concerned… that I’ll reproduce.

Europe is overpopulated, the world will soon be in the same condition, and if the self-reproduction of man is not rationalized… we shall have war.

I’m not particularly a feminist, but if you get women off the animal cycle of reproduction and give them some say in how many children they’ll have, immediately the floor will rise.