What is outside my mind means nothing to it.

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

Is there no way out of the mind?

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

Imagination is the secret and marrow of civilization. It is the very eye of faith.

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

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

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

The real question is not whether machines think but whether men do.

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

The march of the human mind is slow.

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.

Every thought is, strictly speaking, an afterthought.