The psychiatric study of women prisoners in the city of Málaga during the Spanish Civil War provides a starting point for a two-part analysis of the gendered tension between biology and morality. First, the relationship of organic psychiatry and bio-typologies to, in turn, liberalism and neo-Thomist Catholicism is discussed. The supposedly ‘biological’ roots of conditions such as hysteria and their link to women's revolutionary behaviour are examined. Second, prison records are used to examine the material conditions of women in the city and the gendered construction of their moral culpability during the revolution. Both medical science and Catholic doctrine could be exploited in declaring the indissolubility of gendered morality.