About the ongoing debate on power and evil in Middle Earth, how is this shown within the Fellowship itself, which is to me the ultimate arena, it is these people who have really claimed our attention and through whom we experience the story.
Within the Fellowship there are two types of power as exercised among men. Boromir is the son of the most powerful man in the West, the Steward of Gondor. When Denethor comes into the story we see what kind of power is the pattern for Boromir, an aristocratic, autocratic, dynastic power, one which demands obedience and feudal fealty. Boromir can't understand why they can't just take the Ring and use it; power is there to be used. He never doubts his ability to control the Ring; Faramir his brother does, and we see the different ideals of power they embody, and why Denethor prefers Boromir to Faramir.
Aragorn, although descended of kings and entitled to claim the crown of Gondor represents another kind of power altogether, almost a revolutionary power. He is like a guerilla leader, fighting in the hills. At first Boromir refuses to recognise him as a leader at all, but as the quest progresses the Steward's son realises that under Aragorn's tattered clothes is indeed the King. Aragorn, for all his high blood, is power from below, by assent. A leader but also a listener. The character of Aragorn, and also of Faramir, a very similar kind of hero, shows what kind of kingdom there will be after the war if there is to be an afterwards at all.
But thrown into this world of power is another kind of power, that of the hobbits.
Frodo has in his grasp a power far beyond that of Boromir or Aragorn, but he desists from using it, making him a catalyst, almost a passive centre around which others must fight and strive for power.
The hobbits set no value on power, only on friendship, loyalty, love of their homes and kin and a sense of right. Both Aragorn and Boromir have much to learn of hobbits and are in themselves challenged by their little companions' values. When in the book Glorfindel tries to bring Frodo on to Rivendell Frodo resists strongly, not wanting to leave his friends in danger. When the Elf wants to hurry Sam berates him because Frodo is suffering. They may all be on the same side but their motivation is very different.
When Aragorn lets Frodo go, both in the book, by not following him and in the film by a last valedictory meeting, Aragorn has completed his lesson and has let power go to in order to complete his quest, somewhat in the manner of hobbits. But Boromir, more used to the idea of taking and using power and suborned by the Ring, does try to seize this power, and tries to take the ring from Frodo.
Gandalf calls Boromir a 'leader of men' and it is this desire to take power and to lead that lets the Ring into his mind and makes him see the hobbits as obstacles; 'curse all halflings to death and darkness!' he shouts when Frodo escapes from him. On the other side of Amon Hen Aragorn is practising the opposite kind of power, letting Frodo go with his blessing; he knows that this war will not be won by this kind of power, that Sauron can never be beaten at his own game, but only by things he does not understand, by refusal to dominate, by sacrifice and by love. Boromir, proud and powerful, finds this a hard lesson to learn. It is the two youngest hobbits, the least powerful of all, who teach him.
In the book Gandalf says Pippin and Merry 'saved' Boromir, and in the film too his love for the little pair leads him to try to save them at the cost of his own life, a self-sacrifice that wipes out his attempt to overpower Frodo. Even dying he wants to make sure they are rescued, saying to Aragorn 'they took the little ones...'
Just musing, no offence to fans of Boromir, Aragorn or the hobbits.. :-)