besides, how can you cheat a cheater?

As he was about to leave, she said, "Murtagh." He paused and turned to regard her. She hesitated for a moment, then mustered her courage and said, "Why?" She though he understood her meaning: Why her? Why save her, and now why try to rescue her? She had guessed at the answer, but she wanted to hear him say it. He stared at her for the longest while, and then, in a low, hard voice, he said, "You know why.

Do not become so attached to any one belief than you cannot see past it to another possibility. Brom to Eragon

Anger is poison. You must purge it from your mind or else it will corrupt your better nature.

A hatchling, that is what you are. A hatchling struggling into the world. I may be younger than you in years, but I am ancient in my thoughts. Do not worry about these things. Find peace in where and what you are. People often know what must be done. All you need to do is show them the way — that is wisdom.

It’s better to be sworn to an honest fool than to a lying scholar

Keep in mind, Eragon, that no one thinks himself a villain, and few make decisions they think are wrong. A person may dislike his choice, but he will stand by it because, even in the worst circumstances, he believes that it was the best option available to him at the time.