[Boromir88]

I don't know about the Weathertop stab and Shelob's sting...I'll have to go back and look. I certainly don't agree that Frodo was punished for not destroying the Ring. Something we are told that was impossible for anyone's will, and of the time, possibly only Frodo had the strength to get it to Mount Doom.

"Frodo indeed ‘failed’ as a hero, as conceived by simple minds: he did not endure to the end; he gave in, ratted. I do not say ‘simple minds’ with contempt: they often see with clarity the simple truth and the absolute ideal to which effort must be directed, even if it is unattainable....
'I do not think that Frodo’s was a moral failure. At the last moment the pressure of the Ring would reach its maximum - impossible, I should have said, for any one to resist, certainly after long possession, months of increasing torment, and when starved and exhausted. Frodo had done what he could and spent himself completely (as an instrument of Providence) and had produced a situation in which the object of his quest could be achieved. His humility (with which he began) and his sufferings were justly rewarded by the highest honour; and his exercise of patience and mercy towards Gollum gained him Mercy: his failure was redressed.'~Letter 246

Do you think Frodo had 'failed'. Tolkien leaves the interpretation up to the reader. Since Frodo gave in and didn't destroy the Ring does this make him a failure? Maybe, but let's consider all the circumstances, trials, and most of all unattainable goal of destroying the Ring. Aye, Frodo's quest was a set failure from the start, or at least Frodo himself would not be able to destroy the Ring. What's important that I would like to note here (and why I don't think Frodo is punished for not destroying the Ring) is at the end...his failure was redressed. Frodo did fail to destroying the Ring himself, however two important qualities in Frodo (Pity and Mercy) won him his own salvation and his failure was redressed:

'But at this point the 'salvation' of the world and Frodo's own 'savation' is achieved by his previous pity and forgiveness of injury. At any point any prudent person would have told Frodo that Gollum would ceratinly betray him, and could rob him in the end. To 'pity' him, to forbear to kill him, was a piece of folly, or a mystical beleif in the ultimate value-in-itself of pity and generosity even if disastrous in the world of time. He did rob him and injure him in the end- but by a 'grace' that last betrayal was at a precise juncture when the final evil, deed was the most beneficial thing any one could have done for Frodo! By a situation , created by his 'forgiveness', he was saved himself and releived of his burden.'~Letter 181

Frodo's act of pity and forgiveness to Gollum wins him his own salvation. And it is Eru who rewards him by relieving him of the burden of the Ring and destroying it. In this case of Frodo's failure to destroy the Ring, I don't think he was punished in anyway...I actually think he was rewarded!

There is one failure that comes to the top of my head that is punishable...and that is a failure to fulfill an oath. Oaths have a strong power in Middle-earth. If you make an oath you better be prepared to live up to it or face the consequences. Just ask the Men of Dunharrow or Feanor. A good exchange between Elrond and Gimli happens which I think highlights the good and the bad of oaths. Of course, Gimli sees the positive side of oaths, and Elrond (being the pessimist he is ) sees the negative:

...'You may tarry, or come back, or turn aside into other paths, as chance allows. The further you go, the less easy will it be to withdraw; yet no oath or bond is laid on you to go further than you will. For you do not yet know the strength of your hearts, and you cannot foresee what each may meet upon the road.'
'Faithless is he that says farewell when the road darkens,' said Gimli.
'Maybe,' said Elrond, `but let him not vow to walk in the dark, who has not seen the nightfall.'
'Yet sworn word may strengthen quaking heart,' said Gimli.
'Or break it,' said Elrond. `Look not too far ahead! But go now with good hearts! Farewell, and may the blessing of Elves and Men and all Free Folk go with you. May the stars shine upon your faces!'~The Ring goes South

If you fail to fulfill an oath there's no doubt you will be punished. But I don't think Frodo was punished in the sense that Lin Carter argues.