It is due to the Elvish soul’s profound orientation towards and powerful formative influence over its body that, should an Elf be killed, its natural lot—at least according to Tolkien’s original but later abandoned idea of Elvish reincarnation—was for it eventually to consent to being born again through natural childbirth. Even so, though the soul’s “memory” of its former body and power over its new body was so great that over time it would impress upon its new body the same physical appearance as the old (Morgoth’s Ring 233). The formative power of the Elvish soul over the body, moreover, is such that Tolkien eventually found therein the solution to the problem he, again like St. Thomas, came to see in the idea of reincarnation, namely that the reborn body would still seem to be a different body—and therefore the reborn person a different person—from the one that existed before.
As I noted in an earlier post, it was Tolkien’s conceit of reincarnate Elves that had particularly offended the Catholic sensibilities of Tolkien’s acquaintance Peter Hastings, and prompted him to write Tolkien asking if the latter had not in fact “over-stepped the mark in metaphysical matters” (Letters 187). Tolkien at that time had responded by asserting that Elvish reincarnation, even if it were “bad theology,” was nevertheless not bad “metaphysics,” since he did “not see how even in the Primary World any theologian or philosopher, unless very much better informed about the relation of spirit and body than I believe anyone to be, could deny the possibility of re-incarnation as a mode of existence, prescribed for certain kinds of rational incarnate creatures” (Letters 189, emphasis original). From a Thomistic standpoint this is an extravagant claim, for in chapter 153 of his Compendium Theologiae, for example, Thomas argues that because the soul is united to its body as its form, meaning that the body is proper to the soul as its matter, in order for the soul to be embodied a second time, it must be united to the numerically same body as before, making its reincarnation in a different body impossible. (On Thomas’s critique of reincarnation, see Marie I. George, “Aquinas on Reincarnation,” The Thomist 60, no. 1 : 33-52.) It is perhaps not to be surprised at, therefore, that eventually Tolkien’s own, tacit Thomism seems to have got the better of him, for despite the confidence of his reply to Hastings, he shortly thereafter began entertaining his own doubts as to the workability of Elvish reincarnation. As his son Christopher observes, his father came to see the idea of Elvish reincarnation as “a serious flaw in the metaphysic of Elvish existence” (Morgoth’s Ring 363). Tolkien himself wrote that the idea “contradicts the fundamental notion that fëa and hröa were each fitted to the other,” whereas the reincarnate body, having different parents, presumably would not be the same but a different body, and therefore a grievance to the reborn Elvish soul (ibid.). In a passage cited by Christopher in The Peoples of Middle-earth, Tolkien even goes so far as to claim that the now abandoned belief in Elvish reincarnation was “a false notion, e.g. probably of Mannish origin” (390n17). One solution that occurred to him, mentioned in an earlier post, was the notion that the Elvish soul or spirit, rather than being re-embodied through natural child-birth, was instead given a new body by the Valar under Eru’s guidance and permission, yet a body still “of the same form and shape” as it possessed previously (Morgoth’s Ring 339, 362, and 364). Tolkien seems, however, to have come to regard even this solution as untenable, as he went on to entertain the further possibility that “the ‘houseless’ fëa was itself allowed (being instructed) to rebuild its hröa from its memory…,” a process Tolkien at last described as nothing less than an Elvish “resurrection of the body” (364). (On Tolkien’s developing views on Elvish reincarnation, see Devaux, “Elves: Reincarnation” in Drout, ed. J.R.R. Tolkien Encyclopedia, 154-5; ed., Tolkien, l’effigie des elfes (Geneva: Ad Solem, 2005); and Verlyn Flieger, “The Curious Incident of the Dream at the Barrow: Memory and Reincarnation in Middle-earth,” in Tolkien Studies 4 (2007): 99-112.)