Buffon, Species and the Forces of Reproduction.

Throughout the Histoire naturelle Buffon was ever aware of epistemological issues involving the reproduction of species, the only beings in nature. By the 1760s he had come to believe that empirical evidence, the source of all human knowledge, revealed that reproduction was a physical process, involving a common living (minute, active, and lively) matter and material forces, all of which he traced to the foundational force of gravitational attraction.