Your mind’s got to eat, too.

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

Strength of mind is exercise, not rest.

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

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

Understanding is a very dull occupation.

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

The mind of man is capable of anything.

Brains are the only things worth having in this world.

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

The march of the human mind is slow.

The sleep of reason produces monsters.

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