ABSTRACT

The famous theory of generation that Buffon proposed in his Histoire Naturelle in 1749 was one of the first serious attacks against the concept of preexisting germs, which had prevailed since the late seventeenth century. He introduced two main notions: “organic molecules,” i.e., the particles of which living beings were made, and the “interior mold” that organized these particles during development and throughout the life of the individuals. According to him, this interior mold was transmitted from one generation to another without essential modifications, so that each mold was characteristic of a given species and ensured the constancy of it in the course of the centuries. In the theory of 1749, thus, the morphogenetic information mostly lay in the mold, while the organic molecules had little specificity. However, in the late 1730s or the early 1740s, Buffon had had other conceptions on generation, of which some vestiges can be found in the text of 1749. In this earlier theory, the mold had few if any signification in the process of organization. On the other hand, in his texts of the 1770s, Buffon almost never spoke of the molds any longer, and focused on the properties and role of the molecules. It seems that his theory evolved during his career, and that the dialectics of molds and organic molecules changed significantly. In particular, the emphasis on the molds seemed to be only a passing step of this evolution. Here we analyze these changes and their consequences on Buffon’s conception of life.