The essay above is splendid. However, it seems unlikely to me that
Bombadil is
Aule. The difficulty of identifying him as Aule is that Aule loves to make things. Aule is most akin to
Melkor of all the Valor and consequently of all the Valor most like
Sauron, Melkor's servant, the difference being that Aule loves the making more than the possessing of artifacts.
Like Aule Bombadil clearly takes little delight in possessing which he understands as a tremendous burden. Even the brooch he takes from the barrow treasure is to ornament
Goldberry and remind him of her who wore it long ago. However, there is no indication that Bombadil loves making things. His only love seems to be Goldberry.
He seems to delight in the
creatures of the world. However, he has no concern for the great happenings of the world. In this too he differs from the Valor. For the Valor have a great love of the First Born especially and the followers to a lesser degree. Aule especially loved to teach the
Elves; indeed (if my memory serves) he loved teaching the inhabitants of
Arda so much that he created a
race whose only interest would be learning his arts, namely the dwarfs, which rather displeased Illuvatar.
Tom may delight in
men and
hobbits and elves and even learn of their doings from people like farmer Maggot, but he has little interest in collaborating in their affairs. He has so little concern for the affairs of others that one would almost think him completely self absorbed living in his own world, but that he so willingly helps the hobbits in their need.
It is clear that Bombadil is not concerned with the affairs of Arda. He also does not seem to be interested in making things. Yet he does manifest one concern for Arda in his brief appearance (and I have not read his
tales so I do not know whether others appear there). He brings Goldberry the last of the lilies so that she can preserve them for spring. However, even this seems to be a concern more of
the River daughter than of Tom. Goldberry (who may be
Maiar) still remains Tom's only real concern.
From this my conclusion is that
Tom Bombadil is not
Valar nor Maiar. For the Valar create Arda through their music and they and the Maiar come to Arda to form it according to their vision and both to delight in and direct the affairs of Children of Illuvatar. Tom doesn't seem to have any direct interest in creating artifacts or in fashioning and tending the flora and fauna of Arda or directing and aiding the affairs of Elves and Men.
This is also a good indication that Tom Bombadil is not Illuvatar from whose thought came the
Ainur and who directed their music and who is father of the First Born and the Followers. Illuvatar is
the father of all and is extremely interested in the affairs of all mentioned. Although his role is most subtle and mysterious and his purposes moreso, he is very interested in all the affairs of Arda. He is surely the mysterious power at work greater than
the ring refered to by
Gandalf. It was he I think, perhaps through
Ulmo (who knows the secret foundations of the world and directs the currents of the
Great River and beneath the Misty Mountanins and who also knows more secrets of
Eru than any other) Illuvatar arranges for
Bilbo's finding of the ring. His subtle providence and no 'chance' brings Tom Bombadil to the rescue of the hobbits from Old Man Willow. His hand is certainly involved in the happenstance of the fellowship of
Gollum and the two hobbits in their journey to
Mordor. Illuvatar is very subtle in his direction of the affairs of
Middle Earth and none know his mind completely, but he is most interested in the affairs of Men and Elves and hobbits.
Concerning Bombadil as being fatherless, we should note that Illuvatar is father of all and alone truly fatherless. Tom Bombadil may be known to the elves as fatherless, but he is known by many names. He does not so name himself. The elves call him fatherless, but they could call the Valar and Maiar fatherless too. It is strange that Bombadil should be so named. Perhaps, the elves call Bombadil fatherless because he came into being with Arda and to the Elves it seemed he should have a father, whereas the Valar and Maiar came to Arda from outside and are not coeval with Arda. No, he is not Illuvatar.
The most intriguing aspect of Tom is his mastery of the world. He knows the world very well. He knows the tune for every creature, it seems. And since, as someone else remarked, Arda was created by music, it might be said that in knowing the tune for each, Tom truly knows what each thing is. He is master because he knows things deeply and also from the beginning. Tom Bombadil is, but what or who he is, I do not know. He knows and Eru.