Imagination is the secret and marrow of civilization. It is the very eye of faith.

The highest possible stage in moral culture is when we recognize that we ought to control our thoughts.

The mind of man is capable of anything.

Don’t lose your mind unless you have paid for it.

Your mind’s got to eat, too.

A mind lively and at ease can do with seeing nothing, and can see nothing that does not answer.

To be too conscious is an illness—a real thoroughgoing illness.

As is the face, so is the mind.

The universe is an object of thought at least as much as it is a means of satisfying needs.

The real question is not whether machines think but whether men do.

Sanity is madness put to good uses; waking life is a dream controlled.

What a torture to talk to filled heads that allow nothing from the outside to enter them.

Madness need not be all breakdown. It may also be breakthrough.