“Habits form a second nature.”

The form follows the function.

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.

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.

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.

Our own heart, and not other men’s opinion, forms our true honor.

What is reality? An icicle forming in fire.

Art is the one form of human energy in the whole world, which really works for union, and destroys the barriers between man and man.

I don’t think of form as a kind of architecture. The architecture is the result of the forming. It is the kinesthetic and visual sense of position and wholeness that puts the thing into the realm of art.

Anything which must be understood by millions of people is so hopelessly divorced from how it is that it becomes a form of fiction.

Autobiography begins with a sense of being alone. It is an orphan form.

Discrimination, in all its forms, is bad for business.

Language forms a kind of wealth, which all can make use of at once without causing any diminution of the store, and which thus admits a complete community of enjoyment; for all, freely participating in the general treasure, unconsciously aid in its preservation.