DOCTOR: If I knew exactly what the problem was, I would have fixed it by now.

FITZ: Doesn't this TARDIS have some sort of self-diagnostic system? A "fault locator" or something?

DOCTOR: It does.

FITZ: So why not use that to tell you what's wrong?

DOCTOR: It's faulty.

DOCTOR: You're torturing sentient beings to test their telepathic abilities? And you call them creatures? You label them evil? It never fails to amaze me just how conceited, egotistical and downright thoughtless human beings can be. You have such unparalleled capacity for... caring... yet you seem totally inept at putting it into practice.