The True Master.

[mormegil]

Originally Posted by Boromir

So, it's beyond even Sauron's power to throw the Ring away.

Of course it is. It is Sauron and He is It. He poured his own power into it and he is blind to see that others may wish to destroy it because his lust for power is so great that he can only see others doing the same. Of course it was never shown if anybody could destroy the ring because Frodo failed, though I like to think Sam would have done it .

The relationship between Sauron and the ring , if you will forgive me for using this word, creates synergy.

By definition

syn·er·gy
1. The interaction of two or more agents or forces so that their combined effect is greater than the sum of their individual effects.
2. Cooperative interaction among groups, especially among the acquired subsidiaries or merged parts of a corporation, that creates an enhanced combined effect.

Originally Posted by SpM

Or is the will of the Ring an aspect of Sauron's own will? Might it be argued that Sauron and the Ring are essentially one being, albeit a divided one, and that neither is therefore the master?

They are one although divided, that I agree with, but Sauron is the sentient whereas the ring is just an inanimate that has a will in that it reflects the will of its master, Sauron. Now this would make sense because if somebody else were to take the ring and were able to claim the power they would then be the master of the ring.