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

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

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

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.

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

Understanding is a very dull occupation.

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

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

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

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

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

What is outside my mind means nothing to it.

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