Diversification or sensory unification? Controversies around the senses in fin de siècle culture.

This article analyses the evolutionist discourses on the senses that emerged in the late 19th century, when theories on the evolution of species were in full sway. Drawing on newspapers, essays and medical literature, this article aims to set face to face the two currents of thought that I have identified regarding sensory evolution: the one that stressed the value of the progressive specialisation of the senses as evidence for human evolution mainly supported by Max Nordau, and the one which regarded the sensory regrouping, exemplified by the phenomenon of synaesthesia, as the true symptom of evolution, strongly supported by Victor Segalen. A close examination of their arguments will provide clues concerning their relative position vis-à-vis the theory that stressed the exceptional nature of humankind among all living beings.