The march of the human mind is slow.

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

Brain, n. An apparatus with which we think that we think.

From a man’s face, I can read his character. If I can see him walk, I know his thoughts.

What is outside my mind means nothing to it.

Every thought is, strictly speaking, an afterthought.

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.

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

Brains are the only things worth having in this world.

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

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.

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