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

Any man could, if he were so inclined, be the sculptor of his own brain.

The brain is an unreliable organ, it is monstrously great, monstrously developed. Swollen, like a goiter.

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

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.

If anything affects your eye, you hasten to have it removed; if anything affects your mind, you postpone the cure for a year.

Though this be madness, yet there is method in’t.

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

Every thought is, strictly speaking, an afterthought.

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

Strength of mind is exercise, not rest.

Sooner or later if the activity of the mind is restricted anywhere, it will cease to function even where it is allowed to be free.