Immortality

The preoccupation with immortality in a great many of Plato's dialogues rests on both moral and speculative considerations. In the Phaedo, where Socrates discusses the question while awaiting execution, several arguments are advanced. The doctrine of recollection suggests that the soul possessed knowledge before its union with the body; the argument from simplicity holds that as an immaterial and therefore incomposite being, the soul cannot be dissolved; and the argument from the soul's participation in the Form of Life maintains that "whatever the soul possesses, to that she comes bearing life," so that the soul can never admit death, its opposite. The philosopher, on this view, has been practicing a kind of separation from the body throughout his life, and death completes the process.

The moral dimension of Plato's teaching appears most vividly in the myths. In the Republic, the Myth of Er describes souls choosing their next lives after witnessing cosmic justice, the dead rewarded or punished according to their earthly conduct. The connection between immortality and justice, treated more fully under the idea of Justice, runs through these myths: if the soul persists, then the moral quality of a life carries consequences beyond this life, and the divine judgment of souls in an afterlife may be necessary for perfect justice to be done.

Plato's arguments proceed on two assumptions that later thinkers have questioned: that the soul is a substance capable of existing apart from the body, and that its immateriality entails its simplicity and therefore its indestructibility. Whether these assumptions hold is a question that occupied all subsequent discussion.

The arguments of the Phaedo became, for the Western tradition, the starting point for philosophical discussion of immortality. Aristotle's response turns on a denial of the first premise: if the soul is the form of a living body rather than a separate substance, then the question of survival becomes the question, treated in the chapter on Soul, of whether a form can exist without the matter it organizes.

Aristotle's theory of the soul differs fundamentally from Plato's. Where Plato treats the soul as an independent substance, Aristotle defines it as the form or actuality of a living body. On this view, the soul is to the body what sight is to the eye: the substantial form which, in the case of living things, confers upon matter not only the act of existing but also the act of being alive. Since, according to Aristotle's general theory of form and matter (discussed more fully under the ideas of Form and Matter), substantial forms exist only in union with matter, it would seem to follow that when the body perishes, the soul perishes with it.

The exception, if it is one, concerns the intellect. In a celebrated passage of De Anima III.5, Aristotle distinguishes the active intellect from the passive and declares that the active intellect is "separable, impassible, and unmixed," and that it alone "is immortal and eternal." Whether this active intellect belongs to the individual soul or is rather an impersonal principle operating in all human minds, Aristotle does not make clear. The Arabic commentators, notably Averroes, held the latter view; Aquinas argued for the former. The ambiguity of the text has sustained both readings.

In the Nicomachean Ethics, Aristotle treats happiness as attainable within a complete human life and passes lightly over the question of whether the dead share in any good or evil. He demands only "a complete term of life" for happiness. In those passages where he describes contemplation as godlike, he speaks of making ourselves immortal so far as we can, but this seems to refer to the possession of a godlike quality in this life rather than the promise of a life hereafter.

The ambiguity of Aristotle's position on the intellect's separability became a central problem for medieval philosophy, where the requirements of revealed religion pressed the question of individual survival with an urgency Aristotle himself did not share.

Lucretius, following the Epicurean philosophy, holds that the soul, like everything else in the universe, consists of atoms. The atoms of the soul differ from those of the body by their roundness, smoothness, and mobility, but they are material nonetheless, and fewer in number than the atoms of the flesh. On this view, it is not the materiality of the soul but rather its divisibility into parts which accounts for its mortality. The soul grows with the body, is affected by wine and disease, and when the body perishes, the soul, as Lucretius writes, is "dissolved, like smoke, into the high air."

The practical and moral purpose of this argument is no less important than its physical basis. Lucretius dedicates his poem to "driving headlong forth that dread of Acheron" which, as he sees it, troubles human life from its inmost depths and overspreads all things "with the blackness of death, allowing no pleasure to be pure and unalloyed." Where others see in the human fear of death a natural desire for immortality, Lucretius holds that it is the dread of immortality, and particularly of punishment in an afterlife, which causes the fear of death. We have nothing to fear after death, he argues, if death is the end: "He who exists not, cannot become miserable."

Lucretius counsels not despair but contentment. The wise person, on his view, departs from life as a guest departs from a feast, satisfied and grateful. The connection between this teaching and the question of moral sanctions, treated more fully under the ideas of Good and Evil and Pleasure and Pain, is that morality may be sustained without recourse to rewards and punishments in an afterlife.

The position of Lucretius represents the most fully articulated denial of immortality in the ancient world. Mill, in a later century, will argue along similar lines that morality needs no supernatural sanctions, though he concedes their utility where they are believed.

Plotinus, writing six centuries after Plato, develops the Platonic arguments for immortality with greater philosophical precision. In Enneads IV.7 he offers a systematic refutation of materialist accounts of the soul. The soul cannot be a body, he argues, because bodies are divisible and composite, whereas the soul's capacity for self-reflection and intellectual vision requires a unity that no arrangement of material parts can provide. The very activity of reasoning about the soul's nature, on this view, demonstrates that the soul transcends the physical order.

Within the Neoplatonic system, the individual soul occupies a place in a cosmic hierarchy. The One, which is absolutely simple and beyond being, generates Intellect, and Intellect in turn generates Soul. The individual human soul is a lower expression of this universal Soul, and its descent into a body is, in a sense, a forgetting of its higher origin. When the soul turns inward, away from the senses and toward contemplation, it recovers its connection to the eternal. Death, on this account, is the final stage of this turning: the soul sheds the body and returns to its source. There is no divine judgment in the later Christian sense, but rather a natural reascent, the completion of a movement that the philosophic life has already begun. The relation between contemplation and the soul's nature is discussed more fully under the ideas of Soul and Mind.

If the soul is truly eternal and its kinship with the intelligible world is as Plotinus maintains, then the visible world is not the whole of reality, and the life of contemplation becomes, not a leisure of the few, but the recovery of a condition natural to the soul as such.

Plotinus transmitted the Platonic vision of the soul's immortality to the Christian world, though Augustine would alter it in important respects. For Plotinus, the soul's return to its source is a natural ascent available to the philosopher through contemplation; for Augustine, the soul is fallen and cannot ascend by its own effort, but must receive its restoration as grace.

Augustine, while inheriting from Plato and Plotinus the conviction that the soul survives death, departs from the Neoplatonic view in several respects that bear directly on the doctrine of immortality. For Augustine, each soul is created once by God, joined to one body, and destined for a single, irreversible judgment. There is no reincarnation and no gradual purification through successive lives. The soul's fate is determined within the span of a single earthly existence, a view connected with the linear conception of history discussed under the idea of Eternity.

In the City of God, Augustine divides humanity into two cities: the city of God, whose citizens love God above self, and the earthly city, whose citizens love self above God. After death, souls are assigned to one city or the other, and the assignment is permanent. The final books treat the resurrection of the body in considerable detail. Augustine maintains, against the Platonists, that the body is not the soul's prison but its natural companion. The resurrected body will be incorruptible, freed from pain and decay, reunited with the soul for eternity. That "hell, which also is called a lake of fire and brimstone," he writes, "will be material fire and will torment the bodies of the damned." These dogmas go far beyond the merely philosophical proofs of the soul's immortality.

In the Confessions, Augustine's grief over the death of his unnamed friend in Book IV reveals how the question of immortality bears upon the moral and emotional life of the individual. The promise of an afterlife does not eliminate sorrow, but it redirects the restless heart toward God, in whom alone, Augustine holds, it can find rest.

With Augustine, the doctrine of immortality becomes inseparable from the doctrines of divine judgment, grace, and the resurrection of the body. The philosophical question of whether the soul survives is, in his thought, subordinated to the theological question of what awaits it, a question that Aquinas would later attempt to answer with the resources of Aristotelian philosophy.

Aquinas faces a difficulty peculiar to his philosophical position. He accepts Aristotle's definition of the soul as the form of the body, which, on the general Aristotelian theory (discussed under the ideas of Form and Matter), would seem to entail that the soul perishes when the body does. Yet he also accepts the Christian doctrine of the soul's immortality and the resurrection of the body. His argument proceeds on the premise that since thinking involves universal notions, and since forms can be universal only apart from matter, the intellect which abstracts and receives abstractions must itself be immaterial. "The intellectual principle which we call the mind or the intellect," he writes, "has an operation per se apart from the body. Now only that which subsists can have an operation per se." The human soul, therefore, is a subsistent form, capable of existing in and of itself.

Yet Aquinas insists that the separated soul is incomplete. "The soul separated from the body is in a manner imperfect, as is every part separated from its whole." Since, furthermore, Aquinas agrees with Aristotle that every act of understanding involves imagination, he must explain how the soul can function at all when separated from the body. His solution is that the soul, when apart from the body, has "a mode of understanding by turning to simply intelligible objects, as is proper to other separate substances," but that this mode is not natural to it. Bodily resurrection is therefore not an arbitrary miracle but the fulfillment of the soul's natural inclination to be reunited with its body.

The Supplement to the Summa treats the details of resurrection with considerable precision: the condition of the risen body, the state of its organs, the difference between the bodies of the blessed and the damned. These questions reflect the conviction that immortality is not the soul's escape from matter but the perfection of its union with the body.

Aquinas's argument attempts to corroborate both the soul's survival after death and the Christian dogma of the resurrection. Descartes, while affirming the same conclusion, proceeds on entirely different metaphysical grounds: rather than a subsistent form that retains an aptitude for matter, he posits a thinking substance so completely distinct from body that its very simplicity renders it immune to natural destruction.

Descartes approaches the question of immortality through the distinction between thought and extension, rather than through the Aristotelian distinction between form and matter. In the Meditations, the mind or soul is established as a thinking substance, and the body as an extended substance, and these two substances are held to have nothing in common. Since the mind is unextended, it has no parts; since it has no parts, it cannot be divided; and since it cannot be dissolved into components, it cannot be destroyed by any natural process. Descartes does not claim to prove that God, who created the soul, could not annihilate it, but only that the soul's nature renders it immune to the kind of dissolution that destroys bodies.

The philosophical arguments for immortality which Descartes and Locke advance, as Adler observes, do not differ essentially from those offered by Plato and Plotinus without recourse to religious faith. What distinguishes Descartes's position is the sharpness of the mind-body distinction. The mind and the body are so completely different in kind that the destruction of the one has, on this theory, no bearing on the survival of the other. The question of how the soul relates to the body is treated more fully under the ideas of Mind and Soul.

Yet the very completeness of the distinction raises a difficulty that Descartes himself acknowledges. He writes that he is "not lodged in my body as a pilot in a vessel" but is "very closely united to it." If mind and body share no properties whatever, the manner of their union and interaction during life remains obscure, and the question of how an unextended substance can move an extended body has occupied philosophers from Descartes's time to the present.

Those philosophers who, like Descartes, think they have grounds for affirming the existence of the soul as an immaterial substance also have grounds for affirming its immortality. Locke, however, will press a question Descartes does not raise: whether the survival of a soul-substance, without the continuity of consciousness that constitutes personal identity, is in any morally relevant sense the survival of the same person.

Locke introduces into the discussion of immortality a distinction that bears importantly on the question of what, precisely, is said to survive death. In the chapter "Of Identity and Diversity" in the Essay Concerning Human Understanding, he distinguishes between the identity of a substance, the identity of a man as a living organism, and the identity of a person. A person, for Locke, is a thinking, conscious being that can consider itself as itself across time. What constitutes personal identity, on this view, is not the persistence of a soul-substance but the continuity of consciousness, the ability to remember and appropriate one's past experiences.

The bearing of this analysis on immortality is considerable. If a soul-substance were to survive death without any continuity of consciousness, the person, in Locke's sense, would not have survived. Conversely, if consciousness were somehow transferred to a different substance, the person would persist even though the substance changed. The question, treated under the idea of Same and Other, of what constitutes identity over time thus becomes central to the moral significance of immortality.

Locke also engages in the kind of probabilistic reasoning about an afterlife that Pascal had proposed. "When infinite happiness is put into one scale, against infinite misery in the other," Locke asks, "who can without madness run the venture?" If, wagering on immortal life, "the good man be right, he is eternally happy"; but if he is mistaken, "he is not miserable, he feels nothing." This is not a proof of immortality but a calculation of the prudence of living as if it were true. The question of divine judgment, however, requires on Locke's principles that the person who is judged be conscious of the acts for which judgment is rendered.

Locke's analysis requires that any account of immortality specify not merely the survival of a substance but the survival of a conscious self. Kant, building on this requirement, will argue that the moral purpose of survival demands more still: the surviving person must be capable of infinite moral progress, which is why immortality becomes, in his thought, a practical postulate rather than a speculative conclusion.

Kant's treatment of immortality proceeds in two stages which correspond to the two Critiques. In the Paralogisms of the Critique of Pure Reason, he examines and rejects the speculative arguments for the soul's persistence. The argument from the soul's simplicity, as formulated by Plato and repeated by later philosophers, is criticized on the ground that even a simple being may have intensive quantity and therefore be capable of "diminution in reality" through "an infinite series of smaller degrees." More generally, Kant holds that there can be no valid theoretical argument for immortality because there can be no scientific knowledge of things beyond all possible experience. What he calls "the paralogisms of rational psychology" are intended to expose the dialectical futility of both proofs and disproofs of immortality, in the same way that the cosmological antinomies, discussed under the idea of Infinity, expose the untenability of arguments about the infinity of time and space.

In the Critique of Practical Reason, however, Kant affirms immortality as a practical postulate. "The perfect accordance of the will with the moral law," he writes, "is holiness, a perfection of which no rational being of the sensible world is capable at any moment of his existence." Since this perfect conformity is nonetheless demanded by the moral law, it "can only be found in a progress in infinitum towards that perfect accordance," and such infinite progress requires the postulate of an immortal life. Immortality thus becomes, along with the existence of God and the freedom of the will, one of the three postulates which Kant holds to be indispensable conditions of the moral life.

The distinction between theoretical knowledge and practical faith, which underlies Kant's entire treatment, has consequences for the way in which the moral argument is to be understood. It is not a proof in the speculative sense but a postulate, something that practical reason requires even though theoretical reason cannot demonstrate it. The relation between morality and religious belief is discussed more fully under the ideas of Duty and God.

The opposite view is taken by those who, like Aristotle and Mill, hold that happiness is a temporal good attainable on earth. If the summum bonum does not require an infinite duration for its realization, then the moral argument for immortality loses its force, and the question reverts to the speculative sphere where Kant himself has declared it unanswerable.

Mill's treatment of immortality is concerned less with the speculative question of the soul's nature than with the practical question of whether morality requires supernatural sanctions. In Utilitarianism, he examines whether the promise of heaven and the threat of hell are necessary supports for moral conduct. While he does not deny their utility, neither does he admit their indispensability. "There is evidently no reason," he declares, "why all these motives for observance should not attach themselves to the utilitarian morality, as completely and as powerfully as to any other." He stresses "the possibility of giving to the service of humanity, even without the aid of belief in a Providence, both the psychological power and the social efficacy of a religion."

In the Three Essays on Religion, published posthumously, Mill takes up the evidence for immortality directly. The dependence of mental life upon the brain, he observes, suggests that consciousness ends with death; yet he concedes that certainty on this point is not available. What he insists upon is that moral life should not be made to depend on the resolution of this uncertainty. The summum bonum, on Mill's view, is a temporal happiness attainable on earth and by purely natural means, and the service of humanity provides a sufficient object for moral devotion. The relation between happiness and virtue, discussed under the ideas of Happiness and Good and Evil, does not, on this view, require an afterlife for its completion.

Mill does not go as far as Lucretius in regarding the belief in immortality, with its attendant possibility of everlasting torment, as itself an immoral doctrine. But he shares with Lucretius the conviction that a life well lived does not require the expectation of rewards or punishments beyond the grave.

Mill's position represents, in a sense, the opposite of Kant's moral argument. Where Kant holds that the moral law requires us to postulate immortality as a condition of achieving the highest good, Mill maintains that morality can be adequately grounded and made effective without recourse to any doctrine of an afterlife.