Even when the experts all agree, they may well be mistaken.

Fear is the main source of superstition, and one of the main sources of cruelty. To conquer fear is the beginning of wisdom.

Man is a credulous animal, and must believe something; in the absence of good grounds for belief, he will be satisfied with bad ones.

What we need is not the will to believe, but the wish to find out.

When the intensity of emotional conviction subsides, a man who is in the habit of reasoning will search for logical grounds in favor of the belief which he finds in himself.

Bad philosophers may have a certain influence; good philosophers, never.

There will still be things that machines cannot do. They will not produce great art or great literature or great philosophy; they will not be able to discover the secret springs of happiness in the human heart; they will know nothing of love and friendship.

No matter how eloquently a dog may bark, he cannot tell you that his parents were poor, but honest.

We have in fact, two kinds of morality, side by side: one that we preach, but do not practice, and another that we practice, but seldom preach.

Aristotle could have avoided the mistake of thinking that women have fewer teeth than men, by the simple device of asking Mrs. Aristotle to keep her mouth open while he counted.