The mind of man is capable of anything.

The highest possible stage in moral culture is when we recognize that we ought to control our thoughts.

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

The march of the human mind is slow.

Understanding is a very dull occupation.

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

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

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

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

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

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

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

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