Although immortality literally means “not mortal,” its more
specific and commonly used meaning refers to a conscious entity, or a part of
that conscious entity, not being subject to non-existence by death and
eternally existing, in whole or in part, once it exists. Some immortal entities, such as God or gods, are
believed to have always existed and are not subject to death. All known animals, including humans, however,
are mortal—meaning, in the least, their physical body dies. Numerous philosophies and theologies,
however, maintain that the death of the body does not entail the nonexistence
of conscious entity, in whole or in part.
If the part of the conscious entity (e.g., life force, energy, or atoms)
that continues to exist does not also confer and maintain personal identity
then such immortality is said to be metaphysically thin. If, however, the conscious entity maintains
its personal identity such immortality is said to metaphysically thick. In philosophy of religion, it is the latter
that has received the lion’s share of attention: specifically how it can be
conceived that an individual (human) person can continue to exist beyond the
death of the physical body in such a way that she not only retains personhood but
also her unique identity.
Several options from various philosophical and religious
traditions have been offered as to how a human individual can survive her own
death; these include reincarnation, resurrection (of the body), disembodied
soul, and ethereal (astral) body.
Reincarnation, also known as transmigration of the soul, has the longest
philosophical legacy, and was the type of immortality favored since at least
the time of Pythagoras, and accepted by Socrates (through his mouthpiece,
Plato). In this tradition, some type of
identity conferring essence (e.g., soul) of the person is said to continue to
exist after death and be reborn into another mortal body (with some exceptions)
in perpetuity. Resurrection of the body is
the official doctrine of Christianity.
This doctrine states that once an individual dies (immediately or at
some future time) God will resurrect (and perfect) the individual in his
entirety. This resurrected individual
(including the body) will never die again, and thus is immortal. The idea of humans continuing to exist after
the death of the physical body as a disembodied soul has been discussed in
philosophy since at least the time of Plato, but the ideas major exegesis did
not come until Descartes. Descartes
argued that he was “a thing that thinks” (i.e., a thinking thing, a mind) and
that this thing was his soul. This soul
was an immaterial substance and immortal and separated from the physical body
at the time of death. Whether or not the
soul was ever again joined with a physical body was irrelevant. The essence of a person, and his identity,
was his soul, and his soul alone. The
ethereal (astral) body hypothesis has largely been ignored in philosophy, but
is perhaps best represented in mythologies, folk tales, religious
representations, literature and movies.
It is the idea that a person continues to exist after their physical
death as some sort of ghostly, supernatural immortal apparition that is still
in some way recognizable as the deceased individual.
The question of immortality is closely tied to questions of
personhood and personal identity. Can a
person be essentialized to one or more characteristics that maintain personhood
and their identity? To what extent is a
body necessary for both personhood and identity? If a person is resurrected, is it the same
person or a replica of the original person?
What (if any) identity conferring properties can be used to positively
identify a person who has been reincarnated, resurrected, disembodied, or
Immortality also plays an important role in other areas of
philosophy of religion, including the problem of evil and subsequent
theodicies. For instance, why would an
all-good, all-knowing, all-powerful being (e.g., God) create beings that would
suffer death? Does the death of the
physical body serve a divine purpose?
Why would the knowledge that humans are immortal be hidden from
them? Are immortal persons rewarded or
punished eternally for their actions during their Earthly life? If so, is that just?
The idea that humans and other beings are immortal has
largely been taken for granted for most of the history of philosophy. With the rise of skepticism and atheism in
the Modern Era forward, however, arguments for and against immortality have
become more and more logically complex, and little is taken for granted.