 Diderot was not a physician like La Mettrie, or a “working natural historian” like Buffon, although at one point he wrote that, “It is very hard to do metaphysics or ethics well, without being an anatomist, a naturalist, a physiologist, and a physician” (RH; DPV XXIV: 555). Nevertheless, one of his first publications was the translation of James’ Medicinal Dictionary (1745), and in addition to his enormous activity as the chief editor of the Encyclopédie, which heavily features medical entries, sometimes with his editorial interventions, he was also a serious student of chemistry, including “vital chemistry” (Pépin 2012). Later in life he declared that “there were no books I read more willingly than medical books” (EP; DPV XVII: 510).