Psychiatry is sometimes described as a particularly sexist science, having contributed in the past to derogatory discourses on the inferiority of the so-called "weaker sex", and colluded in practice with the consignment of women to mental institutions. The "mad-doctors" agreed to hospitalize "abnormal" women who dared to rebel against male desires. This article does not question the link between psychiatry and anti-feminism, but considers this history from another angle, by analysing the repercussions of this sexist standpoint on the shaping of medical knowledge, and conversely, on representations of female patients. The British case demonstrates that not all physicians accepted theories about women's mental inferiority, and that such theories were sometimes contested by the patients themselves. "Psychiatric power" was not all-powerful, nor did it necessarily speak with one voice. By exploring the debates surrounding the "weaker brain" theory in nineteenth-century Britain, this paper aims to shed fresh light on the construction (and deconstruction) of psychiatric ideas, and to help understand how the subjects of such ideas-women patients-sometimes succeeded in challenging the views of their doctors, "from below".