[Man of the Old Hope]

I quite disagree that Eru Ilúvatar and the Valar may be compared with Uranus and the Greek Titans and Olympian gods. Insofar as they have charge over various spheres and realms, yes, the Valar do resemble various "Indo-European" pantheons. But at the same time they also strongly resemble angelic powers in Jewish-Christian "mythology", given charge over sundry spheres of the universe. In fact, while Tolkien sometimes calls the Valar, "the gods", and admits that the Valar provide a narrative order of beauty, power, and majesty like the gods of "higher mythology", he also refers to them as "angelic powers" from time to time, and admits that he has conceived of them in such a way that a Christian monotheist, "a mind that believes in the Blessed Trinity", can accept them.

To conceive of the Valar as being merely analogous to the Olympians would, I think, misconstrue the mythology and cosmogony (dare I say, theology?) that Tolkien created in the Valaquenta and the Ainulindalë.

As to the question of a "perfect" Eru conceiving of an evil power like Melkor, let me offer a couple of observations.

First, the relevant texts bear examining:

"There was Eru, the One, who in Arda is called Ilúvatar; and he made first the Ainur, the Holy Ones, that were the offspring of his thought, and they were with him before aught else was made."

This beginning of the Ainulindalë makes it clear that the Ainur, among whom Melkor and Manwë were greatest, were indeed the offspring of the Mind of Eru Ilúvatar.

A bit further on we read:

"But now Ilúvatar sat and hearkened, and for a great while it seemed good to him, for in the music there were no flaws. But as the theme progressed, it came into the heart of Melkor to interweave matters of his own imagining that were not in accord with the theme of Ilúvatar; for he sought therein to increase the power and glory of the part assigned to himself. To Melkor among the Ainur had been given the greatest gifts of power and knowledge, and he had a share in all the gifts of his brethren. He had gone often alone into the void places seeking the Imperishable Flame; for desire grew hot within him to bring into Being things of his own, and it seemed to him that Ilúvatar took no thought for the Void, and he was impatient of its emptiness. Yet he found not the Fire, for it is with Ilúvatar. But being alone he had begun to conceive thoughts of his own unlike those of his brethren."

Several observations may be made regarding this text. First, it is quite clear that the traditional Christian (and to some extent, Jewish) understanding of the biblical character known as Satan (the Adversary) informed Tolkien's portrayal of Melkor and his fall. Melkor, like Satan, is created good and in his arrogance comes to oppose Eru (God). "For in the music there were no flaws" - we may conclude that Melkor did not spring from the Mind of Eru an evil being. Melkor's evil was a thing that developed after he sprang forth from Eru's thought.

Second, you will note that the description of Melkor given here, essentially a description of his fall from goodness (expanded on a bit by the text "Of the Enemies" in the Valaquenta), isn't particularly evil. It seems to be that Melkor is simply impatient. One might even be inclined to think (as a created being) that Melkor's impatience at Eru Ilúvatar's lack of interest in filling the void with creation was right and proper.

And here is the essence of Melkor's evil (indeed, of all evil that opposes God): it is evil because it seeks autonomy from Eru Ilúvatar. Melkor seeks the Imperishable Flame apart from Eru Ilúvatar, with Whom dwells the Flame. Melkor seeks creativity and his own notions of "goodness" apart from Ilúvatar, in impatient attempts at autonomy.

Melkor becomes evil because he, in exercising freedom granted him by Ilúvatar, seeks to define himself, seeks to create and to fill the void, apart from Eru Ilúvatar.

In Christian theology, God is not "good" because he measures up to some abstract standard of good. Rather, "good" is defined as that which reflects God. Neither is God "perfect" because he fulfills an abstract definition of perfection. God is perfect (whole and complete), period. That which is "perfect" therefore is to be understood as that which reflects the perfection, or completeness, of God.

Evil, on the other hand, is that which opposes God. Period. No abstractions of "good" and "evil". Simply God, and that which reflects God, and what opposes God.

It is this theology that formed Tolkien as a Roman Catholic, and I think that it is this theology that informed his conception of Eru Ilúvatar and Melkor's fall into evil (opposition to Eru). Melkor is evil not because in the beginning he matches some abstract notion of "evil", but because he seeks to define himself without reference to Eru Ilúvatar, because he seeks arrogant autonomy from Ilúvatar. He falls into the sort of horrible destructiveness that evil invariably does because in defining himself against and apart from Eru, the Source and Origin of Being, he cuts himself off from the creating and sustaining power that resides only in Eru Ilúvatar and his great theme of creation and is left being able only to corrupt and to destroy what Eru Ilúvatar has made.