DOCTOR: Professor Morgan, have you ever heard the expression “only the used key shines”?

MORGAN: What are you talking about?

DOCTOR: Wherever I go in the universe I invariably meet people like you - intelligent, knowledgeable people who, for reasons I can only guess at, reach a point in their lives when they arbitrarily decide to close their minds to anything new. You make it a point of personal pride to scoff, mock, and ridicule anybody who happens to inhabit a larger universe than the one in which you have chosen to imprison yourself - well that’s your business, you may believe I’m talking nonsense and I can’t help what you personally choose to believe, but I do know this - the only way to learn is to keep your mind open to the input of those who are more knowledgeable than yourself.

“Whatever else happens, I am the Doctor, whether you like it or not.”

“Is that pettiness, or attention to detail? I'm an artist Doctor, an auteur of misery and death, and this is my finest work.”