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

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.

Every thought is, strictly speaking, an afterthought.

The brain may be regarded as a kind of parasite of the organism, a pensioner, as it were, who dwells with the body.

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

What is outside my mind means nothing to it.

Understanding is a very dull occupation.

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

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

Imagination continually outruns the creature it inhabits.

The mind of man is capable of anything.

The universe is an object of thought at least as much as it is a means of satisfying needs.

As is the face, so is the mind.