Every thought is, strictly speaking, an afterthought.

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

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

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

Strength of mind is exercise, not rest.

We need strength, we need energy, we need quickness, and we need brain in this country to turn it around.

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

my mind is
a big hunk of irrevocable nothing

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

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

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

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

Imagination continually outruns the creature it inhabits.