Let's see if I can answer this without writing an epistle...
Question:
[quote="Light In The Dark":2djjlbwu]If Frodo kept the Ring just as Gollum had, would he have been utterly consumed by its power, or would he still appear as a Hobbit, and not go into the wretched state of Gollum?[/quote:2djjlbwu]
Answer:
Physically, after hundreds of years, Frodo's bodily changes are somewhat unpredictable. Gollum was in possession of the Ring for hundreds of years, while Bilbo had it for less than 100. This means that the Ring, after it left Gollum, left a more profound effect on Gollum than it did on Bilbo. The Ring was what was keeping Gollum alive, since the Ring was 99% of who he was. But the Ring could not hold onto Bilbo, and he slipped into normal life (and the normal aging process) quite easily. So, although each person is different, if Frodo had held the Ring for as long as Gollum did, and then lost it, then he would have turned out quite a lot like Gollum.
Question:
[quote="Light In The Dark":2djjlbwu]Is it really the corruption of Men/Other Races of Middle Earth, or is it truly the Power that the Ring holds?[/quote:2djjlbwu]
I'm not 100% sure of what the question is, so I'll rephrase it into what I think you mean: When men possess the Ring, is it the Ring that corrupts them, or their own "sin" (if you will) and desire that corrupts them?
Answer:
I look at it this way. The Ring has a certain amount of evil power in it. It is constant. Every person and being in Middle Earth has a different amount of power to stop the power of the Ring. Hobbits, as a rule, are very resilient and immune (though not totally) to the Ring's power. On the other end of the scales, Men are some of the weakest creatures in this respect. So, although a Man's intentions may be right, he has little power to resist the Ring, and the Ring doesn't have much trouble subduing him. So where does the corruption itself come from? Does it come from the Ring, or does the Ring merely awaken the "sin" in the bearer's heart? Putting my Christianity aside, and looking at Middle-Earth as neutrally as I can, I believe that Tolkien intended that it was the Ring that corrupted beings. The Ring gave the bearer power, and as the saying goes, "Power corrupts. Absolute power corrupts absolutely." So, the actual corrupting was done by the Ring, but the resistance was put up by the individual, and the individual was responsible for how much of a resistance they put up.
Question:
[quote="Light In The Dark":2djjlbwu]Is it truly Gollum's fault for ending up the way he is, or was he just simply misguided, and rejected by those around him? Was it Gollum's own weakness that he turned to who he is, or was it the Ring's power?[/quote:2djjlbwu]
Answer: Although this is much like the last question, it deserves answering because it deals with a specific example. I believe that it was not Gollum's fault for becoming corrupted, but it was his responsibilyt to hold out against the Ring as much as possible. He failed in this respect. He pretty much sold himself to the Ring the moment he saw it. But one must remember: So did Deagol. Deagol was actually the first to see it, and the first to sell himself to it. Either:
1. Gollum happened to be faster and stronger that day.
2. The Ring sensed more weakness in Gollum than it did in Deagol, so it forsook Deagol and chose Gollum.
or
3. The Valar (or Iluvatar) was overseeing the whole thing, and that power saw something in Smeagol (Gollum) that would, in the end, save the world. Perhaps if Deagol had retained possession of it, he would have died after losing the Ring, and consequently Frodo would have become a Dark Lord because there was no one to take the Ring from him at the end. Or maybe Sam would have done the hardest thing in the world. Perhaps Sam would have taken hold of Frodo and the Ring, and would have thrown all three (himself, Frodo, and the Ring) into the fire. We'll never know.
I also must address your question about Gollum's depravity being somewhat caused by those around him (who banished him). This was not Gollum's fault, and this was not Gollum's family's fault. This was the Ring's fault. Although Gollum maybe could have held out a little longer against the Ring, ultimately he would have fallen, and he would have been banished anyways. His family was merely doing what was best for the clan.
[quote="Light In The Dark":2djjlbwu]For, it does seem Gollum is meant to have a rather weak character and personality, and the Ring seems to have the exact opposite effect on Bilbo, (Who has a very strong character, portrayed by Tolkien), it advances his life, but he looks much younger then he actually is, and once he loses the Ring, he ages dramatically, as opposed to Gollum... so apparently the Ring's power can change over time? Or, does it depend on the Character of the bearer?[/quote:2djjlbwu]
Like I said earlier, the effect on Bilbo and the effect on Gollum were different, firstly, because of the time period that each held the Ring. But I also do believe that the effect that the Ring has on a person varies from person to person, if only slightly. This is because everyone has different "Firewalls" (if you will) against the Ring. Some are made of paper, some made of solid granite. So, even though the Ring will eventually conquer anyone who possesses it (except the Valar, Iluvatar, or Bombadil), the effect it has on them depends on how strong their original firewall was.
Question:
[quote="Light In The Dark":2djjlbwu]How does the ring have effect on the Istari? Saruman obviously has fell under its sway, and even Gandalf seems weary of it, it even having a weakening effect on himself.[/quote:2djjlbwu]
Answer: We really don't know much about the firewalls that the Istari have. But we do know that, if an Istari were to possess It long enough to break down the wall, then it would wield terrible power, since the Istari are messengers and helpers sent from the Valar and bestowed with certain Valar powers.
[quote="Light In The Dark":2djjlbwu]Sauron is some kind of immortal spirit, but so are the Istari. And if I do recall, Saruman was the strongest of the Istari, so how could he of all be corrupted by Sauron, who was just as himself, (perhaps), but had a Darker side?[/quote:2djjlbwu]
Sauron was more powerful than the Istari (I believe). Sauron was, in the hierarchy, essentially one step down from being one of the Valar. I do not believe that the Istari were this powerful. The Valar did not want to come themselves to Middle-Earth and settle all the troubles, because they wanted the inhabitants to own Middle-Earth for themselves. The Valar didn't want to just come in every time Middle-Earth needed help. But they knew that there were certain odds that the inhabitants of Middle-Earth could never overcome. So, instead of coming themselves, they sent as much help as they, in their wisdom, thought fit to send. Although I have no proof that Sauron was more powerful than the Istari, it just is the most logical. If the Valar sent the second-most powerful, then they might as well have come themselves. No, they decided to help Middle-Earth out just enough to get it through the night.
So how could have Saruman, the most powerful of the Istari, have been corrupted by Sauron? Well, I believe that he wasn't. He was corrupted by being hungry for power. For, again, "Power corrupts. Absolute power corrupts absolutely." Saruman, by no means, had absolute power, so this suggests that Saruman was not wholly corrupted, and that there was some hope for him. That was why Gandalf let him go free. He, much like Gollum, needed to at least be afforded the opportunity to change and come back to the light.
If I didn't cover something, let me know

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