Death is at the very core of the Christian religion. Not only is the cross to be found in cemeteries and places of worship alike, but the premise of the religion is that, by their own action, humans have forfeited immortality. Through abuse of the freedom granted in the Garden of Eden, Adam and Eve not only sinned and fell from grace, but they also transmitted sin to their descendants: the sins of the fathers are visited on the children. And as “the wages of sin is death” (Rom. 6:23), death became the universal fate: “Therefore as sin came into the world through one man and death through sin, and so death spread to all men” (Rom. 5:12). Christian theologians spent the best part of two millennia sorting out these implications and devising ways out of the dire prognosis implicit in the concept of original sin. The main salvation was to be baptism into the death of Jesus Christ (Rom. 6:3–4).
Among early Christians delay in the promised Second Coming of Christ led to an increasing preoccupation with what happened to the dead as they awaited the resurrection and the Last Judgment. One view was that there would be an immediate individual judgment and that instant justice would follow: the deceased would be dispatched forthwith to hell or paradise. This notion demeaned the impact of the great prophecy of a collective mass resurrection, followed by a public mass trial on a gigantic scale. Moreover, it deprived the dead of any chance of a postmortem (i.e., very belated) expiation of their misdeeds. The Roman Catholic notion of purgatory sought to resolve the latter problem; regulated torture would expiate some of the sins of those not totally beyond redemption.
The second view was that the dead just slept, pending the mass resurrection. But as the sleep might last for millennia, it was felt that the heavenly gratification of the just was being arbitrarily, and somewhat unfairly, deferred. As for the wicked, they were obtaining an unwarranted respite. The Carthaginian theologian Tertullian, one of the Church Fathers, outlined the possibility of still further adjustments. In his Adversus Marcionem, written about 207, he described “a spatial concept that may be called Abraham’s bosom for receiving the soul of all people.” Although not celestial, it was “above the lower regions and would provide refreshment (refrigerium) to the souls of the just until the consummation of all things in the great resurrection.” The Byzantine Church formally endorsed the concept, which inspired some most interesting art in both eastern and western Europe.
During its early years, the Christian Church debated death in largely religious terms. The acerbitas mortis (“bitterness of death”) was very real, and pious deathbeds had to be fortified by the acceptance of pain as an offering to God. Life expectancy fell far short of the promised threescore years and 10. Eastern medicine remained for a long time in advance of that practiced in the West, and the church’s interventions were largely spiritual. It was only during the Renaissance and the later age of Enlightenment that an intellectual shift became perceptible. Descartes, the pineal soul, and brain-stem death
The first attempts to localize the soul go back to classical antiquity. The soul had originally been thought to reside in the liver, an organ to which no other function could, at that time, be attributed. Empedocles, Democritus, Aristotle, the Stoics, and the Epicureans had later held its abode to be the heart. Other Greeks (Pythagoras, Plato, and Galen) had opted for the brain. Herophilus (flourished c. 300 bc), a famous physician of the Greek medical school of Alexandria, had sought to circumscribe its habitat to the fourth ventricle of the brain; that is, to a small area immediately above the brain stem. Controversy persisted to the very end of the 16th century.
The departure of the soul from the body had always been central to the Christian concept of death. But the soul had come to mean different things to various classical and medieval thinkers. There was a “vegetative soul,” responsible for what we would now call autonomic function; a “sensitive soul,” responsible for what modern physiologists would describe as reflex responses to environmental stimuli; and, most importantly, a “reasoning soul,” responsible for making a rational entity (res cogitans) of human beings. The reasoning soul was an essentially human attribute and was the basis of thought, judgment, and responsibility for one’s actions. Its departure implied death. The Anatome Corporis Humani (1672) of Isbrand van Diemerbroeck, professor at Utrecht, appears to have been the last textbook of anatomy that discussed the soul within a routine description of human parts. Thereafter, the soul disappeared from the scope of anatomy.
The modern and entirely secular concept of brain-stem death can, perhaps rather surprisingly, find both a conceptual and a topographical foundation in the writings of René Descartes (1596–1650), the great French philosopher and mathematician who sought to bring analytical geometry, physics, physiology, cosmology, and religion into an integrated conceptual framework. Descartes considered the body and the soul to be ontologically separate but interacting entities, each with its own particular attributes. He then sought to specify both their mode and site of interaction; the latter he deduced to be the pineal gland. The pineal was to become, in the words of Geoffrey Jefferson, “the nodal point of Cartesian dualism.”
Before Descartes, the prevailing wisdom, largely derived from Greece, had regarded the soul both as the motive force of all human physiological functions and as the conscious agent of volition, cognition, and reason. Descartes succeeded in eliminating the soul’s general physiological role altogether and in circumscribing its cognitive role to the human species. Descartes’s writings about death show that his concept of the soul clearly implied both mind and the immaterial principle of immortality. It had to mean both things, for no one had ever conceived of survival after death without a mind to verify the fact of continued existence, to enjoy its pleasures, and to suffer its pains.
The relation between body and soul had been discussed in patristic literature, and, because of his Jesuit education, Descartes would have been familiar with these discussions. The church’s interest in these matters was strictly nonmedical, seeking only to reconcile earlier Greek theories with its own current doctrines. Descartes was the first to tackle these problems in a physiological way. With one foot still firmly on consecrated ground (and with Galileo’s difficulties with the Inquisition very much in mind), he sought to give a materialistic, even mechanistic, dimension to the discussion. In this sense, his De Homine (On Man; published posthumously in 1662) can be thought of as an updating of Plato’s Timaeus. His contemporaries viewed Descartes as having delivered the coup de grace to an earlier Greek tradition (dating back to several centuries before Christ) that had claimed that animals, as well as humans, had souls. This had been the subject of much discussion in the early Christian Church. During the 4th century, St. John Chrysostom (onetime archbishop of Constantinople) had denounced the idea, attributing it to the devil, who had allegedly managed by various maneuvers to deceive people as varied as Pythagoras, Plato, Pliny, and even Zoroaster.
Descartes probably was impressed by the central location of the unpaired pineal gland, situated where neural pathways from the retinas converge with those conveying feelings from the limbs. This “general reflector of all sorts of sensation” is, moreover, sited in the immediate proximity of the brain ventricles, from which (according to the wisdom of the day) “animal spirits” flowed into the hollow nerves, carrying instructions to the muscles. In his Excerpta Anatomica, Descartes had even likened the pineal to a penis obturating the passage between the third and fourth ventricles.