| Quote #1
"Mr. Tumnus! Whatever is the matter?" for the Faun's brown eyes had filled with tears and then the tears began trickling down his cheeks, and soon they were running off the end of his nose; and at last he covered his face with his hands and began to howl. (2.28)
Mr. Tumnus has what we might call an overdeveloped sense of guilt. He begins to feel bad for betraying Lucy before he's actually done so. In his mind, thinking of betraying her is just as bad as actually doing so; intent is enough to cause guilt.
| Quote #2
"I say," began Edmund presently, "oughtn't we to be bearing a bit more to the left, that is, if we are aiming for the lamp-post." He had forgotten for the moment that he must pretend never to have been in the wood before. The moment the words were out of his mouth he realised that he had given himself away. Everyone stopped; everyone stared at him. Peter whistled.
"So you really were here," he said, "that time Lu said she'd met you in here – and you made out she was telling lies."
There was a dead silence. "Well, of all the poisonous little beasts – " said Peter and shrugged his shoulders and said no more. There seemed, indeed, no more to say and presently the four resumed their journey; but Edmund was saying to himself, "I'll pay you all out for this, you pack of stuck-up, self-satisfied prigs." (6.24-26)
Peter blames Edmund immediately and completely for the lies he told to make Lucy look bad. While Peter is sort of in the right, because it was wrong of Edmund to lie, his willingness to place blame on Edmund only increases Edmund's own sense of alienation.
| Quote #3
For the mention of Aslan gave him a mysterious and horrible feeling just as it gave the others a mysterious and lovely feeling. (9.1)
Because Edmund feels guilty for making a pact with the Witch, the effect of Aslan's name is to increase his guilt and make him feel worse.