Catelyn Stark: You are no Knight. You have forsaken every vow you ever took.

Jaime Lannister: So many vows. They make you swear and swear. Defend the king, obey the king, obey your father, protect the innocent, defend the weak. But what if your father despises the king? What if the king massacres the innocent? It’s too much. No matter what you do, you’re forsaking one vow or another.

From Game of Thrones – Season 2 Episode 7: ‘A Man Without Honor’ (2×07)