The idea of immortality is central to many religions. Indeed, one of the central questions that religions seek to answer is that concerning what happens to us when we die. According to the Christian tradition, the dead will eventually be raised, judged, and either punished for misdeeds or declared righteous and welcomed into heaven. It is notoriously difficult, however, to make sense of the idea of life after death on which this teaching rests. If we cannot make sense of it, then this will undercut an important element of Christianity.

Reconstitutionalism

One theory of immortality is reconstitutionalism. According to this view, a person is completely annihilated at death, but can (and will) be recreated at a later date, at the Resurrection.

Reconstitutionalism avoids any scientifically suspect commitments to the existence of an immaterial soul that exits the body at death. The main difficulty that its advocates face is that of explaining why we should think that the person created at the Resurrection is the same person that previously died.

Two people can be identical in all respects without being the same person. Identical twins, for instance, which are physically identical, are nevertheless two people rather than one. Two identical twins could, theoretically, be identical not only physically, but in all respects except identity; they could have identical personality traits, and even lead lives where they do precisely the same things. The twins would still, however, be two rather than one. This shows that the mere fact that two people are identical does not entail that they are one and the same.

Suppose that reconstitutionalism is true, that each of us will die, and that God will subsequently recreate us. Our resurrected counterparts will be like us in all respects. As has been seen, though, it is possible for someone to be like us in all respects without actually being us; our resurrection counterparts could simply be our twins. Why, then, should we think that our resurrection counterparts are anything more than perfect replicas of us? Why think that they actually are us?

Augustine, a reconstitutionalist, anticipated this objection to his theory. Augustine’s response to the objection was to suggest that personal identity is grounded in physical continuity, and that God will make our resurrection counterparts by reassembling precisely the pieces of matter of which we are made.

One problem with Augustine’s defence of reconstitutionalism is that the matter in the universe is recycled. What was once a part of Aristotle might have become a part of Aquinas. When God resurrects the two of them, into which resurrection body will this matter be placed?

Dualism

The alternative to reconstitutionalism rests on Cartesian dualism; the only way to make sense of immortality, it seems, is to hold that we are distinct from our physical bodies, and so that when our physical bodies die, we ourselves live on.

This approach, however, does not completely resolve the difficulties associated with Christian eschatology and the idea of the resurrection of the dead. In the Christian dualist tradition, the afterlife is an embodied afterlife; the dead are to be reunited with their bodies, albeit in a glorified state. The question as to what body will be raised therefore remains: will it be a replica, or the real thing? If the real thing, then at what age? And what of the matter that has participated in several people’s bodies?

A further problem with the dualist account of immortality is that it seems to make a mockery of death and resurrection. If Cartesian dualism is true, then in death no one dies; all that happens is that an immaterial soul is stripped of its body. Similarly, if dualism is true, then in resurrection no one is raised; all that happens is that an immaterial soul is restored to the body that it once inhabited. According to dualism, death and resurrection are things that happen to bodies, but not to people, and so are far less significant than is usually thought.