I'm currently struggling my way through Morgoth's ring, and am reading the commentary on the Athrabeth. However, one quote in the commentary is confusing me, and I was hoping someone understood it better than me. In note 7 (p. 382) it is said re: the waning of the elves:
They eventually became housed, if it can be called that, not in actual visible and tangible hroar, but only in the memory of the fea of its bodily form, and its desire for it; and therefore not dependent for mere existence upon the material of Arda.(20) But they appear to have held, and indeed still to hold, that this desire for the hroa shows that their later (and present) condition is not natural to them, and they remain in estel that Eru will heal it. 'Not natural', whether it is due wholly, as they earlier thought, to the weakening of the hroa (derived from the debility introduced by Melkor into the substance of Arda upon which it must feed), or partly to the inevitable working of a dominant fea upon a material hroa through many ages. (In the latter case 'natural' can refer only to an ideal state, in which unmarred matter could for ever endure the indwelling of a perfectly adapted fea. It cannot refer to the actual design of Eru, since the Themes of the Children were introduced after the arising of the discords of Melkor. The 'waning' of the Elvish hroar must therefore be part of the History of Arda as envisaged by Eru, and the mode in which the Elves were to make way for the Dominion of Men.
What is meant by the last sentences, where it's stated that the elves waning must be part of Eru's plan, since the theme of the children was introduced after Melkor's initial discord? Wouldn't it mean that it was not part of Eru's plan, due to the discord? I suppose the question is why can the natural state described not be the actual design of Eru, but also part of “the history of Arda envisaged by Eru”? Additionally, I thought it had been established that the waning was due to the fact that Melkor so thoroughly diffused his power in to Arda, and as such all matter was corrupted in some way, which is mentioned both in the quote I included, and I believe in Laws and Customs.
Anyone able to help me out, or point me towards a good summary of the Athrabeth that explains this?