Did Gandalf Really die after defeating the Balrog?
Gandalf's fight with the Balrog of Moria has raised some questions as to whether Gandalf actually 'died' in the mortal sense of the word. His subsequent reappearance has also brought into question as to who sent him back.
Tolkien's philosophy on working physical effects in the "real-world" of Middle-earth required that a spirit or will actually be a physical entity: Gandalf was a Maia, or angelic being, actually clothed in mortal flesh, and therefore subject to physical harm such as hunger or even injury and death:
"By 'incarnate' I mean they were embodied in physical bodies capable of pain, and weariness, and of afflicting the spirit with physical fear, and of being 'killed', though supported by the angelic spirit they might endure long, and only show slowly the wearing of care and labour."
[The Letters of J.R.R. Tolkien, (#156)]
The Valar had not had much success with direct intervention of events in Middle-earth in their attempts to "shelter" the Children of Iluvatar. Their edict for the Elves to live in Aman led finally, to the rebellion of the Elves and their subsequent exile back in Middle-earth. The Valar's gift of Numenor and the life extension of the Edain also led to their rebellion and blasphemous attempt to conquer the Undying Lands. So when Sauron arose (again) and threatened to dominate all of Middle-earth, the Valar devised a plan by which the inhabitants would be counseled and guided by sage figures in their resistance. The function of the Istari was not to do the job for the peoples of Middle-earth; they were constrained not to show their power or directly confront Sauron with force:
"At this point in the fabulous history the purpose was precisely to limit and hinder their exhibition of 'power' on the physical plane, and so that they should do what they were primarily sent for: train, advise, instruct, arouse the hearts and minds of those threatened by Sauron to a resistance with their own strengths..."
So when Gandalf confronts the Balrog on the Bridge of Moria he faces a real and deadly danger. But he realizes the Quest is in peril and so sacrifices himself to ensure their escape; he falls from the bridge and fights the Balrog, but is himself killed. Yet he returns and is enhanced in power and clothed in white. The question is by whom:
"For in his condition it was for him a sacrifice to perish on the Bridge in defence of his companions, less perhaps than a mortal Man or Hobbit, since he had a far greater inner power than they; but also more, since it was a humbling and abnegation of himself in confirmity to 'the Rules': for all he could know at that moment he was the only person who could direct the resistance to Sauron successfully, and all his mission was in vain. He was handing over to the Authority that ordained the Rules, and giving up personal hope of success.
...So Gandalf sacrificed himself, was accepted, and enhanced, and returned. 'Yes, that was the name. I was Gandalf.' Of course, he remains similar in personality and idiosyncrasy, but both his wisdom and power are much greater. When he speaks he commands attention; the old Gandalf could not have dealt so with Theoden, nor with Saruman. He is still under the obligation of concealing his power and teaching rather than forcing or dominating wills, but where the physical powers of the Enemy are too great for the good will of the opposers to be effective he can act in emergency as an 'angel' - no more violently than the release of St. Peter from prison....
Gandalf really 'died', and was changed: for that seems to me the only real cheating, to represent anything that can be called 'death' as making no difference... He was sent by a mere prudent plan of the angelic Valar or govenors; but Authority had taken up this plan and enlarged it, at the moment of its failure. 'Naked I was sent back- for a brief time, until my task is done'. Sent back by whom, and whence? Not by the 'gods' whose business is only with this embodied world and its time; for he passed 'out of thought and time'. Naked is alas! unclear. It was meant just literally, 'unclothed like a child' (not disincarnate), and so ready to receive the white robes of the highest. Galadriel's power is not divine, and his healing in Lorien is meant to be no more than physical healing and refreshment."
The Valar's plan for the Istari failed; Radagast had become enamoured with the beasts of Middle-earth, Saruman had succumbed to designs of power and a lust for the One Ring, the "Blue Wizards" were rumoured to have founded "magic cults", and even Gandalf was killed, yet Sauron remained and was realizing his effort for complete domination of Middle-earth. This is the point where Gandalf's sacrifice is changed. As Tolkien makes clear, it was not the Valar who returned Gandalf; it was "Authority", he who "ordained the Rules", or more plainly, Iluvatar.
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