There are infinite possibilities of error, and more cranks take up fashionable untruths than unfashionable truths.

Aristotle's metaphysics, roughly speaking, may be described as Plato diluted by common sense. He is difficult because Plato and common sense do not mix easily.

To modern educated people, it seems obvious that matters of fact are to be ascertained by observation, not by consulting ancient authorities. But this is an entirely modern conception, which hardly existed before the seventeenth century.

The more we realize our minuteness and our impotence in the face of cosmic forces, the more amazing becomes what human beings have achieved.

The sentiments of an adult are compounded of a kernel of instinct surrounded by a vast husk of education.

Africans had to be taught that nudity is wicked; this was done very cheaply by missionaries.

I am firm; YOU are obstinate; HE is a pig-headed fool.