A man of Seville is shaved by the Barber of Seville if and only if the man does not shave himself. Does the barber shave himself?

Inferences of Science and Common Sense differ from those of deductive logic and mathematics in a very important respect, namely, when the premises are true and the reasoning correct, the conclusion is only probable.

Freedom in education has many aspects. There is first of all freedom to learn or not to learn. Then there is freedom as to what to learn. And in later education there is freedom of opinion.

Love is something far more than desire for sexual intercourse; it is the principal means of escape from the loneliness which afflicts most men and women throughout the greater part of their lives.

We are faced with the paradoxical fact that education has become one of the chief obstacles to intelligence and freedom of thought.

Those whose lives are fruitful to themselves, to their friends, or to the world are inspired by hope and sustained by joy: they see in imagination the things that might be and the way in which they are to be brought into existence.

Men fear thought as they fear nothing else on earth - more than ruin, more even than death. Thought is subversive and revolutionary, destructive and terrible, thought is merciless to privilege, established institutions, and comfortable habits; thought is anarchic and lawless, indifferent to authority, careless of the well-tried wisdom of the ages. Thought looks into the pit of hell and is not afraid ... Thought is great and swift and free, the light of the world, and the chief glory of man.