“It's like in the great stories, Mr. Frodo. The ones that really mattered. Full of darkness and danger they were. ... Folk in those stories had lots of chances of turning back, only they didn't. They kept going. Because they were holding on to something. ... That there's some good in this world, Mr. Frodo. And it's worth fighting for.”

Sam to Frodo at Osgiliath, in Jackson's adaptation. Not in Tolkien's text verbatim but distilled from his themes.