Immortality plays a major role within Tolkien’s world. It is one of the few works I have read in which a great number of the major players are immortal, in that, if uninjured, they will never die. The Valar, Maiar and Eldar all have the gift of immortality bestowed on them by Ilúvatar. But to them it is not a gift, especially to the Eldar, as they must watch much that was beautiful be destroyed by malevolence, or wither and die from indifference. This remains a theme until the last ship sails from the Havens, when those that had the biggest part in keeping the remains of the beauty of the West in Middle Earth finally leave this responsibility to the hand of Man. This marks the final sundering of the immortal and mortal lands until “the world is mended.” In spite of his heavy usage of immortality, Tolkien is not quick to reincarnate characters. The only characters that are truly reincarnated are Beren, Luthien, Gandalf and Glorfindel, the latter simply because Tolkien reused an elven name from the Silmarillion and later decided that they were one and the same, despite dieing at the hands of a Balrog after the Fall of Gondolin. Beren and Luthien’s reincarnation was an extraordinary gift by Mandos, after Luthien sang a song of such beauty that the couple was allowed to return to Middle Earth to live out mortal lives. It is not clear what happens to men. “Halls of waiting” are mentioned in various places in Tolkien’s writings, but the mechanics behind this is never made clear. It is said that the Valar themselves do not know where the go upon leaving theses halls. Elves are said to awake in new bodies in Valinor, but that is never shown within canon, except This seems to be another instance of Tolkien’s mythology mirroring Christianity. Men and elves both have in effect a “heaven” that they go to when they die, but elves do not have to die to find rest there, but merely take the westward ship.
The fear of death also played a major role in the mythology. The most obvious example being the Numenoreans, who tried many ways to extend their lives, until driven to folly by Sauron, they try to assail the Uttermost West itself in an attempt to gain everlasting life. Instead, they are imprisoned until the “changing of the world,” when Melkor/Morgoth returns and the final battle is fought. In the Lord of the Rings, the most pertinent example of this is the death of Denethor, when he throws himself into a burning pyre. This fear of death also manifests itself in the fear of the dead themselves. The Rohirrim fear the “Paths of the Dead,” and believe that it is certain death for any that tread there; once Aragorn and company raise the dead, both good and evil fled in their wake.
In stark contrast to this fear, most of the protagonists, especially within the Lord of the Rings, do not fear death. Aragorn, like Denethor, picks his time of death, but unlike Denethor, he knows that he has lived a full life, and it is time to hand over his kingdom to his son. Once he has laid himself in the long rest, Arwen follows, laying down on the hill of Cerin Amroth, where they had first pledged their love for each other. Others find redemption in death, most notably Boromir, who, having tried to take the Ring from Frodo, comes to the aid of Merry and Pippin and defends them to the uttermost brink of death. Many other characters are quick to risk their own lives for the chance, however slight, that they may make some small stroke against evil. Beren and Luthien, rush forward to what should have been certain death within Thangorodrim and look pure evil in the eye, somehow escaping with a Silmaril from the crown of Morgoth himself. Then there is Theoden rising up from his throne to fight in battle one last time, facing death head on instead of waiting for it in on his throne at Meduseld; though he falls in the Battle of the Pelennor Fields, by leading his army to Gondor he saves Minas Tirith and helps rid the world of the terror of the Chief of the Ringwraiths by unknowingly leading his niece into battle. Indeed, the Fellowship itself barely had hope of completing the journey to Mordor, much less making it to Mount Doom. In Tolkien’s legendarium there is much honor in undertaking a journey or battle in which there is likely no hope. Those that do and die in their undertaking are honored by those that lived: The Rohirrim save the bodies of those who fell at the fords of the Isen and raise a cairn, Snowmane is interred where he fell in the fields, though Aragorn, Gimli, and Legolas could have immediately followed the orcs to Isengard, they first take the time to see that Boromir is given a fitting burial.
Tolkien was always quick to claim that his writings were not allegorical, but his presentation of death is very similar to death within Christianity. The righteous do not fear death and see it as a release from the pain of the world and as a path to the next, while those who are not righteous fear death and what may come after. Upon death, elves and men awaken in a pure land, free of hurt and evil. The case of men does stray from this allegory; upon waking up in the west after death, they depart to a fate that only Iluvatar knows. Perhaps it is this fear of the unknown that drove so many to attempt to avoid death, instead of trusting Iluvatar.
(I've been trying to post this since Friday morning, hopefully it will finally work this time)
"Tolkien: Medieval and Modern"