If sexual intercourse resulted in female orgasm, her seed became hotter and more refined, therefore conception took place. During the 12th century, Hildegard of Bingen, the head of a convent in the German Rhineland, a prolific writer and a mystic visionary, argued that parents’ feelings toward each other and the moment of conception determined a child’s temperament and character. She also expanded on the Aristotelian model of hotness: “When a woman is making love with a man, a sense of heat in her brain, which brings with it sensual delight, communicates the taste of that delight during the act and summons forth the emission of the man’s seed,” she wrote. “And when the seed has fallen into its place, that vehement heat descending from her brain draws the seed to itself and holds it, and soon the woman’s sexual organs contract, and all the parts that are ready to open up during the time of menstruation now close, in the same way as a strong man can hold something enclosed in his fist.”

Unlike today, the differences between men and women in Hildegard’s time were seen as differences of degree, not kind — even though men were regarded as more perfect than women. Women were considered, by and large, colder and wetter than men. Men’s and women’s bodies were widely seen as having very similar equipment, just in different places. They were supposed to have similar fluids (blood, milk and semen were interchangeable, depending on their temperature conditions). And their experiences of heterosexual sex were also supposed to be similar: Both men and women had to have orgasms because it was only in that heat that new people could be conceived — women needed to experience pleasure in order for fertilization to occur. By the 13th century, in legal terms, women who were raped and became pregnant were presumed not to have been raped.

Fast-forward to the 18th century. The confusion over emission raised the legal question over whether or not rape could result in conception. The historian and author Sharon Block has written of the early modern belief “that conception required a woman’s orgasm meant that a pregnancy could stand for a woman’s consent to an alleged rape.” Legal scholars of the time did not always agree on this matter. The English physician Samuel Farr, in his 1785 book “Elements of Medical Jurisprudence,” declared that “if an absolute rape were to be perpetrated” on a woman, “it is not likely that she would become pregnant.” But the 18th-century British legal authority William Hawkins, in his “Treatise of the Pleas of the Crown,” declared that “the Philosophy of this Notion may be very well doubted of.”

By the 19th century, legal opinion had shifted, at least in some courts. In 1820 an Arkansas appellate judge, in a definitive ruling, called the idea that pregnancy negated rape outdated: “The old notion that if the woman conceived, it could not be a rape, because she must in such case have consented, is quite exploded.”

Modern science has established beyond doubt that a woman who is raped has no control over ovulation, fertilization or implantation of a fertilized egg. Michael F. Greene, a professor of obstetrics, gynecology and reproductive biology at Harvard Medical School, has called Mr. Akin’s comments “just nuts.” That Mr. Akin sits on the House Science and Technology Committee suggests, perhaps, that the Republican Party might as well recruit some historians of medieval and Victorian science as its future science policy advisers. The female body may not be able to shut down conception, but we can at least shut down Mr. Akin’s wild claims.