By Anthony M. Joseph, Professor of History
Few contemporary issues reveal the fruitful intersection of faith and science quite so powerfully as the history of Christian reflection on the nature of the unborn child. The modern Christian understanding of the unborn owes much to the work of scientists, particularly physicians, in defining the nature and development of unborn life in the womb. Christian thought has both inspired and made use of the work of scientists to greatly enrich our understanding of what the unborn child really is.
Over the long expanse of two millennia, there is no question that Christians have accorded a high moral status to the unborn child. The early church saw human gestation as the work of a God intimately involved in the creation of each human being. The embryo was no less the work of God at earlier stages of development than later ones. This view passed from the Scriptures into the teaching of the early church; thence to the Church in the Middle Ages, to the Protestant Reformation, and beyond. Throughout, abortion was regarded as a failure to show due reverence for God’s work and a serious moral wrong—an offense against the work of God in the womb.
Remarkably, the Christian respect for the unborn child stood for centuries alongside the acceptance of an ancient pagan science that did not understand the unborn as fully human from the moment of conception. Rather, the unborn were thought to pass through a series of developmental stages which culminated in full humanness but did not begin in full humanness. This was the theory of delayed ensoulment—that the human soul entered the body not at conception but at some later point in gestation. Aristotle, for example, was taken to believe that the soul entered male embryos at 40 days gestation and female embryos at 80 days.
In the seventeenth century, however, a new science of embryology came into being that ultimately overturned ancient understandings of the unborn. Both Christian reflection and empirical science created this new embryology. Two physicians, the Belgian Thomas Fienus (1567-1631) and the Italian Paolo Zacchias (1584-1659), became the first Christian voices in the West to propose that human life began at or near conception rather than after a succession of physical stages and ensoulments. Fienus theorized that the human soul entered within a few days of conception—it was the soul, he asserted, that directed the subsequent development of the unborn. Zacchias argued for ensoulment at conception in the final volume of his nine-volume treatise Medical-legal questions (1621- 1650). Still later, in 1677, the Dutch scientist Antonie van Leeuwenhoek discovered human sperm. Leeuwenhoek did not entirely understand what he was looking at under his microscope. But his discovery, when combined with developing cell theory, indicated that living organisms had very small, microscopic beginnings. No one was sure how the embryo was first formed in the womb—the mammalian egg would not be discovered until 1826, and knowledge of fertilization came even later—but by 1800 educated physicians held that the embryo was fully human from the moment of conception. There were no “plant” or “animal” stages in human gestation—only a seamless progressive development in which life, motion, and humanness were present throughout, from conception onward.
It is hard to overstate the impact of the new embryology. Inspired by Christian reflection, it in turn influenced Christian thought. Christian theologians abandoned the theory of delayed ensoulment in favor of ensoulment at conception. Impressed by the new embryology, the Sicilian Catholic priest Emmanuel Cangiamila wrote in his work Sacred Embryology that fetuses should be baptized if their safe delivery was in doubt. William G. T. Shedd, a Calvinist Presbyterian, explicitly affirmed immediate ensoulment and remarked that “foeticide is murder in the eyes of God, and of a pure human conscience.” In law, too, the influence of the new embryology could be felt. In Europe and America, legal codes began to reflect its luminous discoveries. In the United States, physicians led the cause for legal protection of the unborn. They persuaded state legislators to enact laws protecting the unborn child from abortion. From 1821 to 1910, every American state produced such a measure.
For centuries, Christians have understood faith and science to be not only compatible but complementary and mutually supportive. There have certainly been bumps along this road, and even saboteurs along the roadside. But the history of the unborn child reflects a powerful and fruitful union between faith and science—a union that, God willing, will be strengthened and solidified over time, come what may.