Palpatine: Good, Anakin. Good. Kill him. Kill him now.
Anakin Skywalker: I shouldn't.
Palpatine: Do it. (Anakin kills Dooku) You did well, Anakin. He was too dangerous to be kept alive.
Anakin Skywalker: Yes, but he was an unarmed prisoner. I shouldn't have done that. It's not the Jedi way.
Palpatine: It is only natural. He cut off your arm, you wanted revenge...