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.

The most potent weapon in the hands of the oppressor is the mind of the oppressed.

Imagination continually outruns the creature it inhabits.

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

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

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

The human mind is an evolutionary product, just like the human body.

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.

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

As is the face, so is the mind.

What is the hardest task in the world? To think.