I am neither Jew nor Gentile, Mahomedan nor Theist; I am but a member of the human family.

These will vary in every human being; but knowledge is the same for every mind, and every mind may and ought to be trained to receive it.

All that I say is, examine, inquire. Look into the nature of things. Search out the grounds of your opinions, the for and against. Know why you believe, understand what you believe, and possess a reason for the faith that is in you.

He who lives in the single exercise of his mental faculties, however usefully or curiously directed, is equally an imperfect animal with the man who knows only the exercise of muscles.

We have ... dreamed so much and observed so little, that our imaginations have grown larger than the world we live in, and our judgments have dwindled down to a point.

There is but one honest limit to the rights of a sentient being; it is where they touch the rights of another sentient being.

You have heard of, and studied various systems of philosophy; but real philosophy is opposed to all systems.