Not all heads have a brain.

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

The mind of man is capable of anything.

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

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

The march of the human mind is slow.

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

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

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

Your mind’s got to eat, too.

What the brain does by itself is infinitely more fascinating and complex than any response it can make to chemical stimulation.

Brains are the only things worth having in this world.

It is far, far better and much safer to have a firm anchor in nonsense than to put out on the troubled seas of thought.