By the end of the eighteenth century male physicians had replaced female midwives as the preferred birthing attendants among the aristocracy and wealthy middle class. How the private world of the lying-in, which derived its authority from women's experiential knowledge of birth and reproduction, had become the domain of the male physician is a complicated and yet often over-simplified story. The eighteenth- and early nineteenth-century debates over the man-midwife illuminate complex and competing discourses surrounding the nature of men, women, and the reproductive body. Through an analysis of selected works published during this period, this essay will highlight the ways in which advocates both for and against the use of male midwives drew upon the wider Enlightenment discourses surrounding natural law, sexual difference and reason to bolster their claims. The repositioning of reproductive matters in the public forum entailed new ways of thinking about how the ‘truths’ of the body were to be ascertained. Birth and maternity increasingly came to be defined as matters that could only be fully managed and understood through detailed, objective, and professional learning, rather than through experiential knowledge. As the traditional foundations for female midwifery came under attack it was the man-midwife who was best able to harness the growing faith in reason and science and to position himself as working in the interests of the emergent public sphere.