This is intended as an explanation of certain points that may seem ambiguous after reading The Silmarillion, as published in 1977 by Christopher Tolkien. I put it forth as fact, despite that some of it borders on personal interpretation. Dispute what you wish, though I believe these ideas provide the most consistent and reasonable whole and will provide arguments for whatever is contested. I have already posted this on my home forum, The Barrow-Downs, and I think people here might appreciate it as well. Due to maximum character restrictions, it will be posted in three sections: Ainur and ëalar, Incarnation, and finally, So What?. On to it, then!
Ainur and ëalar
The origin of the Ainur is fully explained in The Valaquenta, which is contained within The Silmarillion. They are what Tolkien calls ëalar (see HoMe X, p165), which is a being that is naturally discarnate. Ainur may be the only type of ëalar, but it is not necessarily so. Some of the Ainur did not enter into the World, choosing to remain outside of it.
From the ’77:
What is commonly misunderstood about the Ainur is that the two ‘types’ of Ainu, Vala and Maia, are not different races, but merely different stations within Arda. The Valar are ‘the powers’, and Maiar are defined both as ‘the beautiful’, and ‘the people of the Valar’. They serve the Valar, and are defined by that service. If an Ainu is neither counted among the Valar (and there are only 14 of those), or in the service of a Vala, we can only call that being an Ainu, since neither of the titles “Vala” or “Maia” apply.
Tulkas is an example of one of these Ainur who chose to remain outside, though he later did enter into Ëa as an appointed Vala. Ungoliantë, however, could possibly be an Ainu (or at least an ëala) who entered into Ëa of her own accord, unsanctioned by Ilúvatar, and thus was neither Maia nor Vala. It is also possible that she was one of those spirits corrupted by Melkor to his service, as stated in The Silmarillion; but in any case, at the time of her appearance in that story, she was unaffiliated and doing her own thing. Though Tom Bombadil was not a Maia, it is not impossible that he was an ëala or Ainu, much like Ungoliantë. It may be that when the Ainur were given their designations, the potency of their spirit played a part in determining to which class it would belong. But it is also possible that some of the Maiar, and especially unaffiliated ëalar or Ainur, could have had spiritual power to rival some of the Valar.
It is important to note the difference between ëala and fëa. The Children of Ilúvatar possess fëar: it is their spirit, and it is separated from the hröa (or ‘body’) when the body is slain. On the other hand, ëalar are discarnate in nature, and only assume a hröa when they choose to do so.
Ainur and ëalar
The origin of the Ainur is fully explained in The Valaquenta, which is contained within The Silmarillion. They are what Tolkien calls ëalar (see HoMe X, p165), which is a being that is naturally discarnate. Ainur may be the only type of ëalar, but it is not necessarily so. Some of the Ainur did not enter into the World, choosing to remain outside of it.
From the ’77:
Thus it came to pass that of the Ainur some abode still with Ilúvatar beyond the confines of the World; but others, and among them many of the greatest and most fair, took the leave of Ilúvatar and descended into it.
What is commonly misunderstood about the Ainur is that the two ‘types’ of Ainu, Vala and Maia, are not different races, but merely different stations within Arda. The Valar are ‘the powers’, and Maiar are defined both as ‘the beautiful’, and ‘the people of the Valar’. They serve the Valar, and are defined by that service. If an Ainu is neither counted among the Valar (and there are only 14 of those), or in the service of a Vala, we can only call that being an Ainu, since neither of the titles “Vala” or “Maia” apply.
Tulkas is an example of one of these Ainur who chose to remain outside, though he later did enter into Ëa as an appointed Vala. Ungoliantë, however, could possibly be an Ainu (or at least an ëala) who entered into Ëa of her own accord, unsanctioned by Ilúvatar, and thus was neither Maia nor Vala. It is also possible that she was one of those spirits corrupted by Melkor to his service, as stated in The Silmarillion; but in any case, at the time of her appearance in that story, she was unaffiliated and doing her own thing. Though Tom Bombadil was not a Maia, it is not impossible that he was an ëala or Ainu, much like Ungoliantë. It may be that when the Ainur were given their designations, the potency of their spirit played a part in determining to which class it would belong. But it is also possible that some of the Maiar, and especially unaffiliated ëalar or Ainur, could have had spiritual power to rival some of the Valar.
It is important to note the difference between ëala and fëa. The Children of Ilúvatar possess fëar: it is their spirit, and it is separated from the hröa (or ‘body’) when the body is slain. On the other hand, ëalar are discarnate in nature, and only assume a hröa when they choose to do so.

