During the eighteenth century, two church doctrines provided sweeping biblical explanations for most questions about biological diversity: Separate Creation, the idea that all creatures have been created independently of one another by God and organized into a hierarchy ("chain of being") with Man occupying the most elevated rank beneath God; and the 6,000 year limit on the age of the planet.
It is not the average person who questions two thousand years of dogma, but that is what Buffon did: 100 years before Darwin, Buffon, in his Historie Naturelle, a 44 volume encyclopedia describing everything known about the natural world, wrestled with the similarities of humans and apes and even talked about common ancestry of Man and apes. Although Buffon believed in organic change, he did not provide a coherent mechanism for such changes. He thought that the environment acted directly on organisms through what he called "organic particles". Buffon also published Les Epoques de la Nature (1788) where he openly suggested that the planet was much older than the 6,000 years proclaimed by the church, and discussed concepts very similar to Charles Lyell's "uniformitarianism" which were formulated 40 years later.
Buffon was born into the wealth and prestige of the French aristocracy and was educated in law and medicine, but his real interest was nature. He was struck by the diversity of life and was not content with existing explanations of the natural world. What separated him from others was his empirical and philosophical pursuits of causes and explanations beyond the accepted explanations of his time. Buffon's courageous way of looking at the world paved the way for subsequent revolutionary thinkers who are responsible for much of what we know about the natural world.