Georges Louis Leclerc, Comte de Buffon, 1707-1788, French naturalist.
Buffon spelled out his views in his monumental Natural History (Histoire naturelle, générale et particulière), an attempt to present systematically all the known facts of natural science, of which the first volumes appeared in 1749 and the final volumes in 1804.
Buffon rejected Linnaeus's method of classifying species, insisting instead on smooth gradations between not only species but individual organisms. Although he was willing to use anatomical structures to make working distinctions between species, he believed any division into orders, classes, genera, and species misrepresented the variety of nature.
His own experiments, however, caused him to think seriously about the idea of the species. Buffon discovered that animals of different species could be crossbred, but the offspring were infertile: he therefore defined a species as a group of animals that could produce fertile offspring.
Buffon did believe in the idea of the mutation of species, and was the first to suggest the possibility that all animals might have descended or evolved ultimately from a single breeding pair. He rejected the notion of evolution, however, favoring instead a devolutionary theory: animals over time fell off by degrees from their originally perfect state. The broad range of his scientific interest includes subjects of direct import for Frankenstein: comparative geography, the diversification of types within a species, the sexual origin of species, and monsters.
Buffon's most important work in physical anthropology appeared in The Varieties of the Human Species (1749), in which he described the physical and cultural differences between groups of humans. He attributed these differences to the races' accommodation to different environmental conditions.
This well-known theory is alluded to in a letter that Percy Bysshe Shelley wrote his long-time friend Thomas Love Peacock during the Geneva summer of 1816. That citation, in turn, was included in the last letter appended to Mary Shelley's History of a Six Weeks' Tour.