How we cite our quotes: (Page) Vintage Books, 1989
Quote #1
Not, of course, that I fool myself with thoughts that I'm more noble. Pointless, ridiculous monster crouched in the shadows, stinking of dead men, murdered children, martyred cows. (I am neither proud nor ashamed, understand. One more dull victim, leering at seasons that never were meant to be observed.) (6)
The good thing about giving in to nihilist thought is that you have no illusions about your own value. Grendel knows that on some level, he's no better than the brute creatures that annoy him so much.
Quote #2
"The world resists me and I resist the world," I said. "That's all there is. The mountains are what I define them as." Ah, monstrous stupidity of childhood, unreasonable hope...The fire in my mother's eyes brightens and she reaches out as if some current is tearing us apart. "The world is all pointless accident," I say. Shouting now, my fists clenched. "I exist, nothing else." (28)
Despite the fact that Grendel's worried, smelly mother is standing right there and trying to crush him in her arms, he still fights against the fact that she is actually... there. There are two things that Grendel can't bear to accept: 1) that there is a purpose to his and his mother's suffering, and 2) that the world can go on without him. It's a bitter pill to swallow—especially when he's on the brink of extinction in the last moments of the novel.
Quote #3
He told of an ancient feud between two brothers which split all the world between darkness and light. And I, Grendel, was the dark side, he said in effect. The terrible race God cursed. I believed him. Such was the power of the Shaper's harp! (51)
Though Grendel is torn between belief and utter scorn when he hears the Shaper's songs, this particular factoid affects him the most: Grendel is (the Shaper says) a descendant of the cursed Cain (you know, the guy who commits the first murder by taking out his brother, Abel?). Is it possible that Grendel could be suffering from an action that he had no knowledge of and took no part in? If so, and if there really is a God who rules the universe, how can this God be a fair and just ruler? If Grendel seems to be whining a lot about unfairness, don't judge him—someone else, apparently, already has.