Before I begin to speak of my work in mathematics, in physics and in economics separately, I would like to say a few words of the notions of chaos and wild randomness, which I will come back to repeatedly, but which deserve to be spoken about separately. Now chaos is a word that has acquired an extraordinary popularity in recent decades, sometimes for bad reasons because it is misunderstood, but also for a very good reason. And to understand it very well I think it is very important to go back several centuries to the eighteenth century. After Newton's work became known in France it became a topic of extraordinary passion on the part of the intellectuals. In a way the intellectuals were very much wedded to a scheme of things that went back to Aristotle, which said that on earth everything's a mess, and in the heavens everything is perfect. That is, the stars proceed, the planets proceed along well-defined trajectories, the sun is flawless, the moon is flawless. On earth everything is messy, nothing's predictable, everything is terrible. Now Galileo showed that in fact there was some regularity on earth, and there was also messiness in the sky. But Newton was the one who made this idea go through very deeply. It was very shocking to intellectuals in the eighteenth-century because they really took it for granted that in the sky you could predict everything in advance. But on earth the story was embodied in this little rhyme about "for the sake of a nail the horse was lost, for the sake of a horse a battle was lost, for lack of a battle a war was lost, for lack of a war a kingdom was lost". Very tiny differences initially can lead to totally different behaviour. Two people have to meet; one is late; the first doesn't wait; a beautiful match is off. It's very familiar, and Newton gave this totally shattering notion, which in fact in substantial parts of the world we understand; total predictability prevails. Laplace followed by proclaiming a kind of overwhelming imperialist view that one could predict everything precisely; one could also reconstitute the past by knowing the present very accurately; and he wrote it in a very eloquent fashion that was very influential on science. So science, the hard sciences, predicted, and everything else did not. That was something, which the scientists believed, but I think the common man never believed. Underlying all kinds of acknowledgement of the power of science, I believe there was always strong resistance: 'that wouldn't work'.
