immortality, in philosophy and religion, the continuity of human spiritual existence after the death of the body. The concept of immortality is to be distinguished from that of bodily resurrection.
The earlier anthropologists, such as Sir E.B. Tylor and Sir James Frazer, assembled convincing evidence that the belief in a future life was widespread in the regions of primitive culture. Among most peoples the belief has continued through the centuries. But the nature of future existence has been conceived in very different ways. As Tylor showed, in the earliest known times there was little, often no, ethical relation between conduct on earth and the life beyond. M. Jastrow wrote of “the almost complete absence of all ethical considerations in connection with the dead” in ancient Babylonia and Assyria.
In some regions and early religious traditions it came to be declared that warriors who died in battle went to a place of happiness. Later, there was a general development of the ethical idea that the afterlife would be one of rewards and punishments for conduct on earth. So in ancient Egypt at death the individual was represented as coming before judges as to that conduct. The Persian followers of Zoroaster accepted the notion of Chinvat, a bridge to be crossed after death, broad for the righteous, narrow for the wicked, who fell from it into hell. In India the steps upward—or downward—in the series of future incarnated lives have been (and still are) regarded as consequences of conduct and attitudes in the present life. The idea of future rewards and punishments dominated many Christians in the European Middle Ages and is held today by many Christians of all denominations. In contrast, many secular thinkers maintain that the morally good is to be sought for itself, and evil shunned on its own account, irrespective of any belief in a future life.
That the belief in immortality has been widespread through history is no proof of its truth. It may be a superstition that arose from dreams or other natural experiences. Thus, the question of its validity has been raised philosophically from the earliest times that people began to engage in intelligent reflection. In the Hindu Kaṭha Upaniṣad, Naciketas says: “This doubt there is about a man departed—some say: He is; some: He does not exist. Of this would I know.” The Upaniṣads, the basis of most philosophy in India, are predominantly a discussion of the nature of man and his ultimate destiny. Immortality was also one of the chief problems of Plato’s thought. With the contention that reality, as such, is fundamentally spiritual, he tried to prove immortality, maintaining that nothing could destroy the soul. Aristotle conceived of reason as eternal but did not defend personal immortality, as he thought the soul could not exist disembodied. The Epicureans, from a materialistic standpoint, held that there is no consciousness after death, and thus it is not to be feared. The Stoics mostly considered that it is the rational universe as a whole that persists. Individual men, as the Roman emperor Marcus Aurelius wrote, simply have their allotted periods in the drama of existence. However, the Roman orator Cicero finally accepted personal immortality. The Christian St. Augustine, following Neoplatonism, regarded human beings’ souls as being in essence eternal.
The Muslim philosopher Avicenna declared the soul immortal, but his coreligionist Averroës, keeping closer to Aristotle, accepted the eternity only of universal reason. Albertus Magnus defended immortality on the ground that the soul, in itself a cause, is an independent reality. Johannes Scotus Erigena contended that personal immortality cannot be proved or disproved by reason. Benedict de Spinoza, taking God as ultimate reality, as a whole maintained his eternity, but not the immortality of individual persons within him. The German philosopher Gottfried Wilhelm Leibniz contended that reality is constituted of spiritual monads. Human beings, as finite monads, not capable of origination by composition, are created by God. He could also annihilate them. However, in that he has planted in men a striving for spiritual perfection, there may be faith that he will ensure their continued existence, thus giving them the possibility to achieve it.
The German metaphysician Immanuel Kant, admitting that the soul cannot cease by disintegration, suggested that it might end by the loss of its own power. Immortality cannot be demonstrated by pure reason, but it may be believed as a postulate of morality. Holiness, “the perfect accordance of the will with the moral law,” demands endless progress “only possible on the supposition of an endless duration of the existence and personality of the same rational being (which is called the immortality of the soul).” Joseph Butler, insisting that probability is the guide to life, urged, on ethical grounds similar to those of Kant, that immortality should be accepted as probable. G.W.F. Hegel’s philosophy has been interpreted by some as pointing to a cessation of finite individualities in the absolute, and by others as pointing to their persistence as constituents of the absolute. Arthur Schopenhauer conceived ultimate redemption from the misery of life as a lapse from conscious personality into the unconscious universal will.
During the 20th century, the concept of immortality waned as a philosophical preoccupation.