LotR -- Book 6 - Chapter 3 - Mount Doom

[Fordim Hedgethistle]

Frodo fully willed his act. For whatever reason. He was fully aware, fully conscious of what he was doing. He willed his act. But we all saw that one coming, didn’t we? No-one could have withstood the Ring. Frodo was broken by his struggles. He was one little Hobbit, what chance did he have? Yet in the end he fully willed his act. He knew what he was doing & did it anyway.

No he didn't either:

'I have come,' he said. 'But I do not choose now to do what I came to do. I will not do this deed. The Ring is mine!' And suddenly, as he set it on his finger, he vanished from Sam's sight.

This brief moment is really the whole of Frodo's story told in miniature:

'I have come,' he said.

Yes he has, though he "did not know the way" to do it, he managed it -- somehow, against all the odds he did it. That's why he's heroic and good and incapable of choosing to do evil. No-one who is capable of evil could have done what Frodo has done by getting there.

'But I do not choose now'

Frodo says it himself, "I do not choose" -- and in case you missed it he says again:

'I will not'

In this moment, side by side with his declaration of his most heroic act -- the most heroic act in Middle Earth since Bilbo gave up the Ring and Aragorn decided to lead his army to Mordor -- he announces that he no longer "chooses" and has no "will". And for anyone who still hasn't got it:

'The Ring is mine!'...he vanished

Frodo is gone, only the Ring is left.

(See, I'm still lurking about the discussion...)