The worm, an animal formed by spontaneous generation, represents the Virgin Birth of Christ (“I am a worm and no man” of Psalm 22 could be read as a Christological text); the demon is a semi-spiritual creature capable of inseminating a woman; and the virgin, who gives birth parthenogenetically, is also, perhaps, the Virgin Mary. Maaike van der Lugt explores these three themes in medieval embryology through theological, philosophical, and medical texts from the eleventh to the fourteenth centuries. The introductory remarks on the Malleus maleficarum are something of a false trail; van der Lugt's focus is on scholastic accounts of human and animal generation in the Middle Ages, with a few excursions into more general texts.
Van der Lugt convincingly argues that theologians, philosophers and physicians shared a discourse on development in which the Virgin Birth was a common theme. “Divine embryology” was concerned with four aspects of the Virgin Birth: the roles of Mary and the Holy Spirit, the influence of the stars, the timing of the formation of the embryo and its ensoulment, and the source of material from which it was formed. Scholastics made no absolute distinction between nature and miracle, and described the conception and Virgin Birth of Christ in the same terms as ordinary generation. The popular devotion to Maria Gravida also implied a real rather than a miraculous pregnancy: conception by the Holy Ghost was one more way, in addition to parthenogenesis, putrefaction and demonic insemination, by which a virgin could become pregnant.
Van der Lugt then considers the limits of natural generation. Animals could become pregnant without insemination through the action of the wind (by proxy for the pneuma of semen) or the stars, though wind eggs and molar pregnancies were the imperfect results. Spontaneous generation yielded ignoble animals such as insects and vermin, though a search for nobler examples is suggested by medieval legends of barnacle geese, and vegetable lambs, which grew on trees. Medieval scholars accepted the possibility of conception by demons but, unlike later theologians, did not associate it with sorcery, and denied demons generative power, insisting on their borrowing or altering human semen to achieve offspring. Van der Lugt painstakingly compares French and English manuscript and printed sources on demonic reproduction: Merlin, who lacked a human father, is our conductor through a series of accounts of generation by incubi, succubi, and humans; parallels that made it easier to accept the Virgin Birth as a natural rather than a supernatural event.
The chapters on the conception of Christ demonstrate that theologians drew on medical writings, some no longer extant, to describe the development of Christ in utero. Aristotelian embryology, via Arab translations, maintained that the mother provided the substance, not the form, of the embryo. If Christ, as the Nicene Creed stated, “took flesh” of the Virgin but nothing more, then her contribution, as Thomas Aquinas wrote, was no different from that of any other mother. The Franciscan view, articulated by John Duns Scotus, that Mary played an active role in the incarnation, was never accepted as orthodox, though the phenomenon of maternal imprinting—the formation of a foetus in the image of the mother's imagination—seemed to offer a means. One might speculate that the rejection of a formative maternal contribution to the foetus was due in part to theological arguments against a co-redemptrix.
Van der Lugt does not address the wider theological issues or the “social or psychological dimension” of embryological theories. The presentation of primary material, much of it translated for the first time, is the book's strength, making it the most comprehensive account of medieval embryology available. Though the book's narrow focus necessarily leaves some peripheral areas, such as monstrous births and animal/human hybrids, unexplored, the re-establishment of theological embryology as a central theme is illuminating.
