Freud's ‘Critical Introduction’ has many of the markers of a purely neuroanatomical text. But a comparison with contemporary anatomical writings as well as an analysis of the larger scientific, clinical and institutional context of Freud's work suggests important differences. Freud's manuscript was an ambitious enterprise to reform the brain sciences of the 1880s to open them up to nervous conditions that were only poorly accounted for by the predominant German model of a somatically informed psychiatry. It marks an attempt to bridge the two cultures of French and German-speaking neurology, as well as scientific and clinical medicine. By navigating these different contexts, the text provides a clue to the relationship between Freud's early scientific work and his developing psychoanalysis.