My sense of things from the Silmarillion was that even the Ainur are not aware
of all of Eru's thought and not always aware of what each other have thought.
Only Eru alone is knows all. Of the changes that Melkor wrought it is said:
'...no theme may be played that hath not its uttermost source in
me, nor can any alter the music in my despite. Fro he that attmempteth
this shall prove but mine instrument in the devising of things more wonderful,
which he himself hath not imagined.'
And of the knowledge of the Ainur it is said:
And many other things Ilúvatar spoke to the Ainur at that time,
and because of their memory of his words, and the knowledge that each has of
the music that he himself made, the Ainur know much of what was, and is, and is
to come, and few things are unseen by them. Yet some things there are
that they cannot see, neither alone nor taking counsel together; for to none
but himself has Ilúvatar revealed all that he has in store, and in every age
there come forth things that are new and have no foretelling, for they do not
proceed from the
past.
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...each of us is an allegory, embodying in a particular tale and clothed in the garments of time and place, universal truth and everlasting life. (Letters, 163)
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