It struck me that the popularity of Christmas is a matter of web-like consciousness. Childhood conditions us to relax and expand at Christmas, to forget petty worries and irritations and think in terms of universal peace. And so Christmas is the nearest to mystical experience that most human beings ever approach, with its memories of Dickens and Irving's Bracebridge Hall.

Simple perception then is a fallacy. Besides the conscious prejudices that we are aware of imposing on the world, there are a thousand subconscious prejudices that we assume to be actuality.

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.

Isaiah Berlin once said that there are two kinds of writers, hedgehogs and foxes. He said the fox knows many things, the hedgehog knows just one thing. So Shakespeare is a typical fox; Tolstoy and Dostoyevsky are typical hedgehogs. Now, I'm a typical hedgehog. I know just one thing, and I repeat it over and over again. I try to approach it from different angles to make it look different, but it's the same thing.

The real issue is not whether two and two make four or whether two and two make five, but whether life advances by men who love words or by men who love living.

When I open my eyes in the morning, I am not confronted by a world, but by a million possible worlds.

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.