When I spotted this book in my local bookshop, I naturally assumed that it was yet another addition to the frankly enormous number of popular scientific biographies about Charles Darwin. Not that you can ever have too many of those, you understand. Well, I can't, at least—which is why I bought it.
But Niles Eldredge's book takes a refreshingly different approach to discussing Darwin. Instead of the usual chronological descriptions of the key events in Darwin's life, Eldredge analyses the development of Darwin's thinking, primarily from his early notebooks: how, from an originally creationist point of view, Darwin used inductive reasoning from his observations about fossils and species distribution in South America to conclude that evolution does indeed occur. Then, having accepted the fact of evolution, Darwin began to seek a mechanism by which it might occur (John Herschel's mystery of mysteries). When Darwin eventually read Thomas Malthus, his prepared mind quickly saw the analogy with the natural world, and he came up with the idea of Natural Selection (which was still just an hypothesis at this stage).
Then, brilliantly, Darwin turned his logic about-face and began to deduce the implications of evolution by means of Natural Selection, arriving back at his original observations about South America, and at many different new ideas worthy of further investigation. Darwin's hypothesis was beginning to turn into a proper theory. Eldredge credits Darwin with being one of the first people to employ this modern hypothetico-deductive approach to scientific reasoning. People (including Darwin) say there was nothing particularly special about Darwin's way of thinking, but Eldredge is having none of that—and I think he's right.
As co-proposer with the late Stephen Jay Gould of the theory of Punctuated Equilibrium, Eldredge regrets how Darwin, from an early, apparently punctationist position, became more and more of a hard-line gradualist, believing (incorrectly) that gradualism was a necessary requirement for his great theory. Modern day gradualists might not agree with Eldredge, but he makes a good case.
This beautifully illustrated book is certainly worth a read to anyone interested in Darwin—or two reads to anyone who, like me, actually sees some value in the philosophy of science.