"Milieu", "Environment" and "System": the Tranformations of Theoretical Terms in Science, from Modern to Contemporary

The history of science provides many examples of the semantic transformation of theoretical terms that take one direction in a heuristic sense and then acquire another, different, and sometimes contrasting meaning in a new context, even just a few decades later, and in the same historical and epistemological area. This is the case for the term “ evolution ” with reference to living beings. At the time of the Genevan physiologist Charles Bonnet (1720-1793) and his “ preformism ”, the French word évolution denoted the process of the deployment of preexisting forms of living organisms, all already contained in the egg, the flower blossoming from seed, or the butterfly emerging from a caterpillar. Later on, in Charles Darwin’s evolutionism “ evolution ” is something quite different. There is a lesser known case of semantic transformations or permutations of theoretical terms concerns the concept of milieu, that is, the living environment of an organism or parts of an organism. From the onset of the modern era to the present day, words denoting this concept have undergone a significant semantic shift. The relationship between organisms and their environment has become progressively more intimate and more complex.