[Formendacil]

I agree with Galadriel55 that Thorin's quest was not primarily motivated by greed, but I think Tar-Jêx might be onto something here, regardless. Even if Thorin, the character, has more diverse motivations than greed--and I think at the start of his quest, Thorin's home-longing and desire for revenge is much stronger than greed--greed *is* a major factor in The Hobbit. Indeed, I want to say that it's the primary vice explored in the novel.

The main competitor, off the traditional list of seven anyway, would seem to be sloth, but Bilbo, for all his desire to avoid adventures, isn't particularly lazy and even taken as the umbrella vice for cowardice, the development of courage in Bilbo--and in the Dwarves!--through the novel is something of a necessary theme in an adventure story, whereas greed gets a deliberate treatment.

Thorin isn't the only one whose actions are motivated by greed; until the Goblins show up, greed was main motivator for all the participants at the Battle of the Five Armies. Smaug, as a dragon, is the embodiment of greed as much as any of the vices. But I wouldn't say that greed gets a deliberate treatment in The Hobbit if the book's hero were not such a good illustration of the opposing virtues.

Bilbo, like Thorin, longs for home and for the things that are "his." But where Thorin's desire for Erebor grows and darkens until it blots out even recognition that Bilbo has helped him reclaim it, Bilbo's remains focused on the little things: food and his fireplace, and as the book wears on its frequency seems to diminish (this is an impression, rather than something I can point to numbers on), or at the very least seems to shift from pining to a sort of comfort-day-dream in the dreariness and weariness of his adventure.

Bilbo's reward too, is in direct contrast to Thorin's overwhelming greed: despite having a claim to a vast quantity of treasure and a better claim to have liberated it than most of the other claimants (Bard being the main exception), Bilbo is content with no more treasure than a single pony can carry--and he gives away some of that almost immediately, in what is another minor lesson to a greedy character (namely, the Elvenking).

~*~*~*~*~

Apart from The Hobbit, greed crops up in The Silmarillion too--the legacy of the treasures of Nargothrond is an immediate point of contact, and greed for the gems of the Noldor is one of Morgoth's motivators. Even more so than in The Hobbit, though, it's a mixed topic. Pride is everywhere and regarding the Silmarils, I would almost call it lust more than greed. But as the dragonhoard of Glaurung shows, and sheds light back towards Smaug's hoard, Tolkien definitely makes use of dragon treasure a catalyst for greed.