ing 1833–1840, several of which artfully incorporate the best science of the time and had considerable influence on the public and among scientists. One of the treatises, The Hand, Its Mechanisms and Vital Endowments as Evincing Design (1833), was written by Sir Charles Bell, a distinguished anatomist and surgeon, famous for his neurological discoveries, who became professor of surgery in 1836 at the University of Edinburgh. Bell follows Paley’s manner of argument, examining in considerable detail the wondrously useful design of the human hand but also the perfection of design of the forelimb used for different purposes in different animals, serving in each case the particular needs and habits of its owner: the human’s arm for handling objects, the dog’s leg for running, and the bird’s wing for flying. “Nothing less than the Power, which originally created, is equal to the effecting of those changes on animals, which are to adapt them to their conditions.”

Paley and Bell are typical representatives of the intellectual milieu prevailing in the first half of the 19th century in Britain as well as on the Continent. Darwin, while he was an undergraduate student at the University of Cambridge between 1827 and 1831, read Paley’s Natural Theology, which was part of the university’s canon for nearly half a century after Paley’s death. Darwin writes in his Autobiography of the “much delight” and profit that he derived from reading Paley: “To pass the B.A. examination, it was also necessary to get up Paley’s Evidences of Christianity, and his Moral Philosophy…. The logic of … his Natural Theology gave me as much delight as did Euclid…. I did not at that time trouble myself about Paley’s premises; and taking these on trust, I was charmed and convinced by the long line of argumentation” (Darwin, 1887a).

Later, however, after he returned from his 5-year voyage around the world in the HMS Beagle, Darwin would discover a scientific explanation for the design of organisms. Science, thereby, made a quantum leap.

Darwin considered natural selection, rather than his demonstration of evolution, his most important discovery and designated it as “my theory,” a designation he never used when referring to the evolution of organisms. The discovery of natural selection, Darwin’s awareness that it was a greatly significant discovery because it was science’s answer to Paley’s argument from design, and Darwin’s designation of natural selection as “my theory” can be traced in Darwin’s “Red Notebook” and “Transmutation Notebooks B to E,” which he started in March 1837, not long after returning (on October 2, 1836) from his 5-year voyage on the Beagle, and completed in late 1839 (see Eldredge, 2005).