Freud's criticism of the localization project as carried out by Theodor Meynert and Carl Wernicke has usually been seen as marking his break with contemporaneous brain science. In this article, however, I show that Freud criticized localization not by turning his back on brain science, but rather by radicalizing some of its principles. In particular, he argued that the physiological pretensions of the localization project remained at odds with its uncritical importation of psychological categories. Further, by avoiding a confusion of (...) categories and adopting a parallelist reading, Freud was able to develop a fully “physiologized” account of nervous processes. This opened up the possibility for forms of mental pathology that were not reliant on the anatomical lesion. Instead, Freud suggested that lived experience might be able to create a pathological organization within the nervous system. This critique—a passage through, rather than a turn away from, brain science—opened the possibility for Freud's theory of the unconscious and his developing psychoanalysis. On a methodological level, this article aims to show how the intellectual history of modern Europe can gain from taking seriously the impact of the brain sciences, and by applying to scientific texts the methods and reading practices traditionally reserved for philosophical or literary works. (shrink)