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

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

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

The mind is not, I know, a highway but a temple, and its doors should not be carelessly left open.

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

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

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

Not all heads have a brain.

There is no female mind. The brain is not an organ of sex. As well speak of a female liver.

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

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

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

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