All this stuff is mainly concerned with Fall, Mortality, and the Machine..

This extract from one of Tolkien’s letters to a prospective alternative publisher, Milton Waldman, reveals quite well Tolkien’s view of allegory, ‘magic’, technology, art and ‘sub-creation’ as opposed to domination:

For one thing its 'faerie' is too lavish, and fantastical, incoherent and repetitive. For another and more important thing: it is involved in, and explicitly contains the Christian religion. For reasons which I will not elaborate, that seems to me fatal. Myth and fairy-story must, as all art, reflect and contain in solution elements of moral and religious truth (or error), but not explicit, not in the known form of the primary 'real' world. (I am speaking, of course, of our present situation, not of ancient pagan, pre-Christian days.

I dislike Allegory – the conscious and intentional allegory – yet any attempt to explain the purport of myth or fairytale must use allegorical language. (And, of course, the more 'life' a story has the more readily will it be susceptible of allegorical interpretations: while the better a deliberate allegory is made the more nearly will it be acceptable just as a story.)

Anyway all this stuff is mainly concerned with Fall, Mortality, and the Machine. With Fall inevitably, and that motive occurs in several modes. With Mortality, especially as it affects art and the creative (or as I should say, sub-creative) desire which seems to have no biological function, and to be apart from the satisfactions of plain ordinary biological life, with which, in our world, it is indeed usually at strife.

This desire is at once wedded to a passionate love of the real primary world, and hence filled with the sense of mortality, and yet unsatisfied by it. It has various opportunities of 'Fall'. It may become possessive, clinging to the things made as 'its own', the sub-creator wishes to be the Lord and God of his private creation. He will rebel against the laws of the Creator – especially against mortality.

Both of these (alone or together) will lead to the desire for Power, for making the will more quickly effective, – and so to the Machine (or Magic). By the last I intend all use of external plans or devices (apparatus) instead of development of the inherent inner powers or talents — or even the use of these talents with the corrupted motive of dominating: bulldozing the real world, or coercing other wills. The Machine is our more obvious modern form though more closely related to Magic than is usually recognised. I have not used 'magic' consistently, and indeed the Elven-queen Galadriel is obliged to remonstrate with the Hobbits on their confused use of the word both for the devices and operations of the Enemy, and for those of the Elves. I have not, because there is not a word for the latter (since all human stories have suffered the same confusion). But the Elves are there (in my tales) to demonstrate the difference. Their 'magic' is Art, delivered from many of its human limitations: more effortless, more quick, more complete (product, and vision in unflawed correspondence). And its object is Art not Power, sub-creation not domination and tyrannous re-forming of Creation. The 'Elves' are 'immortal', at least as far as this world goes: and hence are concerned rather with the griefs and burdens of deathlessness in time and change, than with death. The Enemy in successive forms is always 'naturally' concerned with sheer Domination, and so the Lord of magic and machines; but the problem : that this frightful evil can and does arise from an apparently good root, the desire to benefit the world and others

—    speedily and according to the benefactor's own plans — is a recurrent motive.

The Letters of J.R.R. Tolkien