Here is the "however": although Tolkien is responsible for (re)establishing all the classic elements of a fantasy novel--the quest, the companions, the magical item--he didn't stick all such elements in a bag, shake them up, and say, "Hey, here's a fantasy!" The elements did not dictate content (in fact, one could argue that Tolkien, like Lewis, was so steeped in Norse and Anglo-Saxon tales and legends, he didn't even realize how consistently he was utilizing such elements or motifs).
Consequently, when Tolkien brings Frodo to Mount Doom, he does not have Frodo simply toss the ring in on the classic justification that he is the hero--ergo, he can do everything!
|Sam & Frodo's trip takes a week. Aragorn attacks|
|Mordor at the top-hand Northwest gate. As the|
|map illustrates, this would distract the eye at Bara-dur.|
The ring has been a true burden, not a token one (ha ha). No one else could have carried it so far, as Gandalf and Galadriel acknowledge when they refuse to take it. By its nature, the ring consumes a person's will. It is the ultimate nothingness which sucks up light and hope and thought. It must have an impact, and its impact must go beyond the physical (although it does weigh Frodo down). Frodo must be affected psychologically in order for the entire trilogy not to be a waste of time. The pay-off must merit the problem.
Frodo doesn't throw the ring in Mount Doom. I know some people consider this a lack of heroism, but to me, Frodo's heroism is everything he has done before arriving at Mount Doom, everything that makes the climax possible. Gollum's arrival is not a deus ex machina; Gollum is there precisely because Frodo made it possible for him to be there. Like his uncle, Frodo spared Gollum's life (Frodo more than once). Frodo used Gollum (in the absence of other guides) to lead him into Mordor. Frodo crossed Mordor despite great weariness, bringing himself, the ring, and Gollum in his wake to the crucial place and exactly the right time.
|Martin Freeman as Bilbo contemplating|
|what to do with the pitiful Gollum.|
Consider that Frodo surely tells Gandalf and Aragorn what occurred at Mount Doom--he did lose a finger! No one reproaches him. No one behaves as if he was a failure. He is, rather, honored by wizards and men and elves. The point is that he got the ring where he said he would against fearful odds, not that he adopted the proper role of "hero" at the proper time.
Tolkien is completely underestimated in this regard. Since he was writing world fantasy and since he created a good versus evil story, his comprehension of basic human nature is sometimes ignored. Granted, C.S. Lewis was a little more obvious and direct in his explorations of human fallibility and variability. But it's all there in Tolkien!