Barbara: What do you care what I think or feel?
The Doctor: Well, as we learn about each other, so we learn about ourselves.
The Doctor: Oh, yes. Because I accused you unjustly, you were determined to prove me wrong. So, you put your mind to the problem, and, luckily, you solved it.
Played by Jacqueline Hill, 1963-1965
First appearance: An Unearthly Child
Last appearance: The Chase