I deny that anyone knows, or can know, the nature of the two sexes, as long as they have only been seen in their present relation to one another.... What is now called the nature of women is an eminently artificial thing --- the result of forced repression in some directions, unnatural stimulation in others. --- John Stuart Mill
Dr. Edward H. Clarke's book Sex in Education, or a Fair Chance for the Girls [1873] was the great uterine manifesto of the nineteenth century. It appeared at the height of the pressure for co-education at Harvard, where Clarke was a professor, and went through seventeen editions in the space of a few years. Clarke reviewed the medical theories of female nature --- the innate frailty of women, the brain-uterus competition --- and concluded, with startling but unassailable logic, that higher education would cause women's uteruses to atrophy!