The paper analy zes the kind of kno wledge on women that has been produced by medicai science since the formation of social medicine in Rio de Janeiro in the nineteenth century. We can observe the emergence of a discourse conceming the feminine sex - a discourse that rests on the notion of psychic degenerateness and that would come to view the female sex as possessing a degenerate base and thus as liable to succumb to the most terrible menaces. This type of discourse, which paints woman as an unwholesome being capable of harming herself and ali society, would serve to ground the effort to make women ever more incapable of managing their own lives and to treat any behavior that fails to correspond to that of a model wife and mother as pathological.