During the first half of the nineteenth century, brain anatomy and physiology began to express innovative ideas that would come to be known collectively as “unconscious cerebration” by the end of the century. The notion of the brain as the body’s motor was called into question as its functioning was linked to unconscious and reflexive processes. This article will explicate the conditions under which the notion of “unconscious cerebration” was introduced into public debates. It will then turn towards the intersection between literary narratives and scientific discourse in order to understand the contribution of literature on three levels: the phenomenology of unconscious cerebration, the etiology of neuroses, and the representation of the artist. The contribution of literature proves to be less an addition to the base of knowledge than a subtle play with writing practices and notions of the contemporary sciences. Through this play, fiction provides a competing and alternative form of knowledge, opening up new epistemological horizons.