okay finn. you started this on discord but i'm making you finish here. why couldn't sauron actually repent and go with eonwe?
Hi, friend! So this is a fun question. Let me get into a little context here first.
After Morgoth's defeat in the War of Wrath, Sauron approaches Eönwë, the herald of Manwë, and renounces his past actions. While it's possible that this repentance may have been genuine, we are also told in The Silmarillion that it was likely motivated by fear.
"When Thangorodrim was broken and Morgoth overthrown, Sauron put on his fair hue again and did obeisance to Eönwë the herald of Manwë, and abjured all his evil deeds. And some hold that this was not at first falsely done, but that Sauron in truth repented, if only out of fear, being dismayed by the fall of Morgoth and the great wrath of the Lords of the West."
- The Silmarillion, pg. 357
While "some" people believe that the repentance was genuine, I would like to direct attention to the context of the lines that I've bolded and underlined. Apologizing because you're afraid of the consequences of your actions is not the same thing as being sorry that you committed them.
If we continue along the same selection, I think there's more evidence that Sauron wasn't sorry for what he did - just that he might be caught and forced to face consequences like Morgoth had.
"But it was not within the power of Eönwë to pardon those of his own order, and he commanded Sauron to return to Aman and there receive the judgement of Manwë. Then Sauron was ashamed and unwilling to return in humiliation and to receive from the Valar a sentence, it might be, of long servitude in proof of his good faith; for under Morgoth his power had been great. Therefore when Eönwë departed he hid himself in Middle-earth; and he fell back into evil, for the bonds that Morgoth had laid upon him were very strong."
- The Silmarillion, pg. 357
Genuine repentance requires that one be willing to make amends for the things that they have done, even if that repentance is painful or humiliating. I do not believe that Sauron truly regretted what he had done in Morgoth's employ; I don't think he was capable of that sort of regret, given the corruption that had so twisted his heart.
Tolkien doubles-down on this in one of his letters:
"He repents in fear when the First Enemy is utterly defeated, but in the end does not do as was commanded - return to the judgement of the gods. He lingers in Middle-earth. Very slowly, beginning with fair motives - the reorganizing and rehabilitation of the ruin of Middle-earth, "neglected by the gods" - he becomes a reincarnation of Evil, and a thing lusting for Complete Power, and so consumed ever more fiercely with hate (especially of gods and Elves)."
- Tolkien's Letter 131
And in its own way, that's very sad. Being incapable of feeling remorse for what he did (only fear of the consequences) lead to Sauron repeating the very same actions again, which only cemented his own doom.
Fear of consequence and genuine repentance are not the same thing. Sauron was self-aware enough to know that and he was certainly familiar enough with the Valar to know that they would know that - and that it is unlikely that they would be moved to pardon him if he were not truly repentant.
Now, the Valar are not omniscient or omnipotent:
“The Valar, being created spirits of high angelic order, are not omnipotent or omniscient.”
- Tolkien's Letters, Letter 156
But in most cases, they're also not stupid and Melkor had already fooled Manwë once with a false plea for pardon.
Let's remember what Manwë experienced with Melkor when he was first captured and eventually released (only to corrupt the Noldor, murder Finwë, steal the Silmarils, make a pact with a primordial being of darkness, and cast the entire world into shadow by destroying the Two Trees - Melkor you naughty boy):
Before the gates of Valmar, Melkor abased himself at the feet of Manwë and sued for pardon, vowing that if he might be made only the least of the free people of Valinor, he would aid the Valar in all their works, and most of all in the healing of the many hurts that he had done to the world. And Nienna aided his prayer; but Mandos was silent.
Then Manwë granted him pardon; but the Valar would not yet suffer him to depart beyond their sight and vigilance, and he was constrained to dwell within the gates of Valmar. But fair-seeming were all the words and deeds of Melkor in that time, and both the Valar and the Eldar had profit from his aid and counsel, if they sought it; and therefore in a while he was given leave to go freely about the land, and it seemed to Manwë that the evil of Melkor was cured.
For Manwë was free from evil and could not comprehend it, and he knew that in the beginning, in the thought of Ilúvatar, Melkor had been even as he; and he saw not to the depths of Melkor’s heart, and did not perceive that all love had departed from him forever. But Ulmo was not deceived, and Tulkas clenched his hands whenever he saw Melkor his foe go by; for if Tulkas is slow to wrath, he is slow also to forget. But they obeyed the judgement of Manwë; for those who will defend authority against rebellion must not themselves rebel."
- The Silmarillion, pg. 86
Having experienced false pardon from Melkor, Manwë was unmoved by pleas for pardon from him after the War of Wrath because he knew that they were not genuine. Sauron is more than intelligent enough to know that going to Manwë and trying to claim that he's sorry when he truly isn't is a one way ticket to the Void.
Is Sauron the most fabulous deceiver to ever exist in Arda? Definitely. Would he be willing to gamble his freedom and presence in the world on being able to deceive a freshly wrathful and still-bloodstained Manwë?
I would hazard to guess that he was smart enough to know how that would probably end for him.
