One of the most successful techniques Tolkien uses in his writing is to use dichotomies within opposing characters, in order to demonstrate where their choices will lead. There are many examples throughout the Lord of the Rings trilogy, where two characters are presented with the same choice, and one makes the wrong decision, acting as a cautionary tale that shows the terrible devastation of this incorrect decision, while the other chooses the right path, and ends in triumph and celebration.
The best examples of this include Boromir and Faramir, both sons of Gondor, both human men who are presented with the opportunity to try to take the One Ring and use it to protect their people. On the one hand, Boromir succumbs to this terrible temptation, tries to take the ring from Frodo, and ultimately ends up losing his life because of it. On the other hand, Faramir has the same choice when Frodo ends up in his hands in Ithilien, but Faramir makes the right choice, lets Frodo go, and ultimately saves Middle Earth by letting the ring-bearer complete his quest to destroy it.
And it’s not just Men who are faced with these choices, these dichotomies go from the smallest beings (hobbits) right up to the most powerful beings (wizards). Another pair of opposites who show what giving in to desire and hubris means are Gandalf the Grey and Saruman the White. Saruman himself presents Gandalf with the choice, that they should join forces and serve the dark lord, and try to claim the ring of power for themselves.
At this point, Saruman has already fallen into darkness and his greed is beyond redemption, which results in him eventually losing Isengard, fleeing to concoct an evil scheme in The Shire, and then being murdered by Grima Wormtongue. On the contrary, Gandalf chooses to stay loyal to his friends and his Istari mission, to help rid the world of evil, for which he is granted the ability to come back as Gandalf the White, and ends up being the hero of many many people’s lives.
Gandalf is the savior of most of the key characters in one form or another, but perhaps his most notable undoing of evil is that of freeing King Theoden of Rohan from the terrible clutches of Saruman. Theoden himself presents another dichotomy of characters, with his counterpart being Denethor of Gondor. So why then is Gandalf able to save and redeem one but not the other? It is clear that both rulers of the respective kingdoms are suffering a terrible malady of the mind.
When the audience first comes across Theoden in the Two Towers, he is a withered man, aged beyond his years, who has abandoned his nice and nephew and seems unmoved by the death of his only son. He is clearly being manipulated by his perverse and cunning advisor Wormtongue, who has poisoned his thoughts and body with Saruman’s magic. Luckily Gandalf is able to rid him of this awful curse in a stunning display of power in his new form as a white wizard, and Theoden returns to himself and his senses and rises to be the king that his people have needed him to be.
In opposition to this is Denethor, who is also clearly suffering sickness of the mind, as his paranoia and self-righteousness lead both of his sons to the brink of death. However, when Gandalf arrives and tries to help Denethor in the same way that he tried to help Theoden, he is unable to get through to the Steward and cure him of his madness and his malady. He tries to implore Denethor to accept help, both his and others, but Denethor is too proud and mighty to admit that he and his rule are failing.
Both Denethor and Theoden are being poisoned by external forces, for Theoden it’s Saruman, for Denethor it’s Sauron’s whisperings and terrible misgivings through the Palantir up in the highest towers of Minas Tirith. But, as with all of Tolkien’s themes and messages, it all comes down to the choices that they make, and the pathways they follow. The difference between the two, and the reason that Gandalf is able to save one and not the other, is simply that Theoden wants to be saved, and Denethor does not.
Theoden chooses the path of hope, the path of action, he decides to fight alongside his people, knowing that he might not come out the other side, but that he will have helped to shape a better future for the generations that come after him. He chooses to accept Gandalf’s aid and guidance, and he ends his story dying on the battlefield, as a brave hero who will be honored forever, and his legends passed down through the ages. Denethor on the other hand, rejects Gandalf’s assistance and advice, believing that he as the Steward knows better. He gives in to despair, and decides that he would rather die than trust in others to come to his defense, and ultimately ends his story as a coward, throwing himself from the rampart and leaving Faramir and Aragorn to pick up the pieces of his neglected kingdom.