This chapter focuses on the emergence, from the Enlightenment, notably represented by Comte de Buffon, to the interwar period, focusing on Oparin and Haldane. It shows how it became intrinsic to the general issue of the theories of the evolution of living beings. The French naturalist Buffon supported spontaneous generation and used it in his theories. Buffon occupied an influent position for a long time, as Intendant of the King’s garden as well as part of the King’s natural history cabinet. Buffon’s central concept regarded the constitution of living matter. He claimed that all the living beings, that is, plants and animals, are constituted with organic molecules, which, according to Buffon, are microscopic, alive and indestructible. Buffon claimed that the origin of species depends on spontaneous generation. Jean-Baptiste Monet de Lamarck presented a developed theory of the transformation of species in 1802.