Man is brilliant at solving problems; but solving them only makes him the victim of his own childishness and laziness. It is this recognition that has made almost every major philosopher in history a pessimist.

The Americans have always been more open to my ideas. In fact, I could earn a living in America just by lecturing. One of my brightest audiences, incidentally, were the prisoners in a Philadelphia gaol - brighter than my students at university.

Imagination should be used, not to escape reality but to create it.

It seemed perfectly possible that, in spite of my certainty of my own genius, I might die of some illness, or perhaps even in a street accident, before I had ever glimpsed the meaning of life. My moods of happiness and self-confidence convinced me that I had a "destiny" to become a famous writer, and to be remembered as one of the most important thinkers of the century.

It was Rousseau who was largely responsible for the problem by giving currency to the idea that freedom can exist without responsibility and discipline.

Criminals interest me, because they're driven by the same desires as we are, but they take these disastrous shortcuts and end up in a real mess.

Turning on the light is easy if you know where the switch is.