AbstractThe emerging area of philosophy of birth is invaluable, first, to diagnose fallacious assumptions about the relation between the womb and reason, and, ultimately, to challenge potentially damaging narratives with major impact on birth care. With its analysis of eighteenth-century epistemic and medical discussions about the role of the uterus in women's reasoning (or lack of reasoning), this article supports two arguments: first, that women's “flawed thinking” was a premise drawn by many modern intellectual men, one that was presented as based upon empirical evidence; and second, that the pervasive construction of the uterus as an element that renders women wild, uncontrollable, and irrational continues to influence contemporary obstetrics (and maybe even to nurture obstetric violence), even as today's medicine and science consider themselves to be free of any such prejudices.This article shows the role that Giacomo Casanova played in debunking these prejudices and presents his short manuscript on the issue as an important contribution to the literature of the Enlightenment, with its argument against women's supposed “natural” inferiority and for the idea that differences in education (rather than anatomical differences) were to blame for women's subordinate position in society.Detailed analysis of the “thinking uterus” debate illuminates the different ways in which various arguments from/by the “anti-uterine” lobby were used to justify the subordination of women: sometimes emphasizing the connection between the uterus and thought and sometimes negating it, but always concluding that women's inferiority is to be found in some known or yet-to-be-discovered anatomical, and mainly sexual, deficiency or problem.