including geology, plant morphology and physiology, psychology, and evolution, and subjected them to severe empirical tests.
There is an apparent contradiction between how Darwin (Fig. 13.1) proceeded in his scientific research and how he described it for public consumption, between what he said in his published writings about his scientific methodology and what he wrote in his notebooks, correspondence, and autobiography.
The opening paragraph of The Origin of Species (Fig. 13.2) reads as follows:
When on board H.M.S. Beagle, as naturalist, I was much struck with certain facts in the distribution of the inhabitants of South America, and in the geological relations of the present to the past inhabitants of that continent. These facts seemed to me to throw some light on the origin of species—that mystery of mysteries, as it has been called by one of our greatest philosophers. On my return home, it occurred to me, in 1837, that something might perhaps be made out on this question by patiently accumulating and reflecting on all sorts of facts which could possibly have any bearing on it. After 5 years’ work I allowed myself to speculate on the subject, and drew up some short notes; these I enlarged in 1844 into a sketch of the conclusions, which then seemed to me probable: from that period to the present day I have steadily pursued the same object.
Darwin claims to have followed the inductionist canon prevalent among British contemporary philosophers and economists, such as John Stuart Mill (1843), and earlier authorities, notably the statesman and philosopher, Francis Bacon in his Novum Organum (Anderson, 1960). The inductionist canon called for making observations without prejudice as to what they might mean and accumulating observations related to a particular subject so that a universal statement or conclusion could eventually emerge from them. Indeed, in one place in his Autobiography, Darwin affirms that he proceeded “on true Baconian principles and without any theory collected facts on a wholesale scale” (Barlow, 1958, p. 119).
The facts are very different from these claims, however. Darwin’s notebooks and private correspondence show that he entertained the hypothesis of the evolutionary transmutation of species shortly after returning from the voyage of the Beagle and, all important, that the hypothesis of natural selection occurred to him in 1838; several years before he claims to have allowed himself for the first time “to speculate on the subject.” Between the return of the Beagle on October 2, 1836, and publication of