I had to think about it, however, before I gave an 'Andrew Lang' lecture at St Andrews on Fairy-stories; and I must say I think the result was entirely beneficial to The Lord of the Rings, which was a practical demonstration of the views that I expressed. It was not written 'for children', or for any kind of person in particular, but for itself. (If any parts or elements in it appear 'childish', it is because I am childish, and like that kind of thing myself now.) I believe children do read it or listen to it eagerly, even quite young ones, and I am very pleased to hear it, though they must fail to understand most of it, and it is in any case stuffed with words that they are unlikely to understand – if by that one means 'recognize as something already known'. I hope it increases their vocabularies.
As for plenilune and argent, they are beautiful words before they are understood – I wish I could have the pleasure of meeting them for the first time again! — and how is one to know them till one does meet them? And surely the first meeting should be in a living context, and not in a dictionary, like dried flowers in a hortus siccus!
Children are not a class or kind, they are a heterogeneous collection of immature persons, varying, as persons do, in their reach, and in their ability to extend it when stimulated. As soon as you limit your vocabulary to what you suppose to be within their reach, you in fact simply cut off the gifted ones from the chance of extending it.
Surely I am 'childish' enough, and that ought to be enough for real children or any one 'childish' in the same sort of way, and never mind if the old chap knows a lot of jolly words. I send you a little piece of nonsense that I wrote only the other day, as evidence of my childishness. Though I have alas! picked up enough grown-up jargon to write in imitation of my elders; and I might say 'it is a neatly constructed trifle, an amusing attempt to penetrate the elf-childishness of an elf-child, if any such thing existed!' (...) Don't bother about the 'opinions'. In fact I write as I do, ill or well, because I cannot write otherwise. If it pleases anybody, large or small, I am as much surprised as delighted. God bless you. Very much love.
Letters of J.R.R. Tolkien
#234 : 22 November 1961