Not all heads have a brain.

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

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

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.

“I think, therefore I am” is the statement of an intellectual who underrates toothaches.

What is outside my mind means nothing to it.

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

Don’t lose your mind unless you have paid for it.

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

In psychoanalysis nothing is true except the exaggerations.

The march of the human mind is slow.