Aristotle, in spite of his reputation, is full of absurdities. He says that children should be conceived in the Winter, when the wind is in the North, and that if people marry too young the children will be female. He tells us that the blood of females is blacker than that of males; that the pig is the only animal liable to measles; that an elephant suffering from insomnia should have its shoulders rubbed with salt, olive-oil, and warm water; that women have fewer teeth than men, and so on. Nevertheless, he is considered by the great majority of philosophers a paragon of wisdom.

There is no logical impossibility in the hypothesis that the world sprang into being five minutes ago, exactly as it then was, with a population that "remembered" a wholly unreal past. There is no logically necessary connection between events at different times; therefore nothing that is happening now or will happen in the future can disprove the hypothesis that the world began five minutes ago.

The reformative effect of punishment is a belief that dies hard, chiefly I think, because it is so satisfying to our sadistic impulses.

To write tragedy, a man must feel tragedy. To feel tragedy, a man must be aware of the world in which he lives. Not only with his mind, but with his blood and sinews.

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.

Artists are on the average less happy than men of science.

We know very little, and yet it is astonishing that we know so much, and still more astonishing that so little knowledge can give us so much power.