The philosopher of science, Thomas Kuhn, developed or published in 1962 a book on scientific revolutions in which he said that you had a paradigm of theories that dominated a certain period and then you had normal science in for a long time following. Then again, you had a major scientific revolution resulting in a new paradigm which then dominated all the thinking for the next 20 or 30 or 50 years of normal science. Well, I went through the history of biology, where we also have many scientific revolutions – just think of the Darwinian one in 1859 – and I found that they do not at all go on like Kuhn says. For instance, let's take the… in the case of Kuhn always a paradigm is totally replaced suddenly by a new paradigm. Well, Darwin, in 1859, when he proposed the theory of natural selection, this was not at once accepted, in fact it took 80 years before it became a majority view. But it competed for this whole period with three other explanatory theories of evolution like… inheritance of acquired characters, mutations, cosmic teleology and so on and so forth. So, I developed gradually ideas in this field that were quite different from the standard opinions of the historians of… of science, most of which had come out of physics. And I first published individual papers, for instance, I did one on Louis Agassiz who was so opposed to Darwin's evolutionary theories after they came out in 1859. And I showed that Louis Agassiz was dominated by a set of concepts and ideas that simply made it impossible for him to accept Darwinian revolution.