Dalla “scala” al “piano”. Appunti per un’indagine interpretativa

During the Eighteenth Century – from Bonnet to Robinet, from Maupertuis to Diderot, and up to Buffon – several new topics of discussion were developed concerning materialism, the critique to finalism, the idea of nature as continuous metamorphosis (as apposed to the static, fixist and discontinuist theories of nature), the advocacy of providentialism, or, to the contrary, of the role of chaos. As a result, scales, prototypes and types have been employed as interpretative hypotheses influencing the main choices and lines of research. In this regard, however, Étienne Geoffroy Saint-Hilaire's work deeply modified the morphological metaphors. The teratologist's eye combined to the mineralogist's perspective established the priority of the material visibility of the living, based on the analysis of its structure rather than of its physiology. The single framework of organistion (unity of composition), on which base every being is formed is thus taken as the condition as well as the limit within which every possible variation in shape is fully justified.