A quote from the two-hour Battlestar Galactica third-season premier that aired last week. (A little background for those unfamiliar with the series: Sharon is a Cylon [humanoid robot] who betrayed her people last season and helped the humans.)
Sharon: Can I ask you a question? How do you know? I mean, how do you really know that you can trust me?
Admiral Adama: I don’t. That’s what trust is.