N'ayant pas d'autres références sous la main, je citerai ici un extrait de l'appendice F du LotR où le Professeur parle de son utilisation du mot "elfe" :
"Elves has been used to translate both Quendi, 'the speakers', the High-elven name of all their kind, and Eldar, the name of the Three Kindreds that sought for the Undying Realm and came there at the beginning of Days (save the Sindar only). This old word was indeed the only one available, and was once fitted to apply to such memories of this people as Men preserved, or to the making of Men's minds not wholly dissimilar. But it has been diminished, and to many it may now suggest fancies either pretty or silly, as unlike to the Quendi of old as are butterflies to the swift falcon - not that any of the Quendi ever possessed wings of the body, as unnatural to them as to Men."
C'est bien le mot "elfe" que Tolkien reprend et non le concept. Il me semble (mais je peux me tromper, c'est de mémoire :-)) que Tolkien parle également dans une lettre (151 ?) de son regret sur l'utilisation du mot "elfe".
Finrod.