Belling the Ring

[Earendilyon]

Originally Posted by The Saucepan Man

And even if mastered by another and used to overthrow Sauron (and Tolkien says that Gandalf is the only one who would have even a chance of acheiving this), the Ring (and thus Sauron) would still be master in the end.

Tolkien discussed the what-if-Gandalf-used-the-Ring scenario in Letter # 246. If Gandalf overcame Sauron, not Sauron but the Ring would be the ultimate winner:

Confrontation of Sauron alone, unaided, self to self was not contemplated. One can imagine the scene in which Gandalf, say, was placed in such a position. It would be a delicate balance. On one side the true allegiance of the Ring to Sauron; on the other superior strength because Sauron was not actually in possession, and perhaps also because he was weakened by long corruption and expenditure of will in dominating inferiors. If Gandalf proved the victor, the result would have been for Sauron the same as the destruction of the Ring; for him it would have been destroyed, taken from him for ever. But the Ring and all its works would have endured. It would have been the master in the end.

Remember, though, that Letter # 246 is a draft; the book doesn't say whether or not a 'clean copy' was actually sent.