DOCTOR: Well, to be fair, I did have a couple of gadgets which he probably didn't, like a teaspoon and an open mind.

DOCTOR: I say, what a wonderful butler. He's so violent.

DOCTOR: To the rational mind, nothing is inexplicable; only unexplained.

DOCTOR: Answers are easy. It’s asking the right questions which is hard.

DOCTOR: Homo sapiens. What an inventive, invincible species. It's only a few million years since they've crawled up out of the mud and learned to walk. Puny, defenceless bipeds. They've survived flood, famine and plague. They've survived cosmic wars and holocausts, and now here they are amongst the stars, waiting to begin a new life, ready to outsit eternity. They're indomitable. Indomitable!

DOCTOR: I tell you, Brigadier, there's nothing to worry about. The brontosaurus is large and placid.

DOCTOR: I had to face my fear… That was more important than just going on living.

DOCTOR: A straight line may be the shortest distance between two points, but it is by no means the most interesting.

DOCTOR: When you get back to Skaro, you’ll all be national heroes. Everybody’ll want to hear about your adventures. So be careful how you tell that story, will you? Don’t glamourize it. Don’t make war sound like an exciting and thrilling game. Tell them about the members of your mission that will not be returning. Like Maro, Vaber and Marat. Tell them about the fear. Otherwise your people might relish the idea of war. We don’t want that.

DOCTOR: Courage isn’t just a matter of not being frightened, you know. It’s being afraid and doing what you have to do anyway.

MASTER: I'd like to try and take the Doctor alive, if possible. If not, I'll blast him out of space! Pity, though.

OGRON: You do not wish to kill him?

MASTER: Of course I do! But I don't know... Rocket fire at long range, I don't know, somehow it lacks that personal touch.

DOCTOR: People who talk about infallibility are usually on very shaky ground.

STEWART: You are giving us a great deal of trouble.

DOCTOR: I'm delighted to hear that.

DOCTOR: Goodbye, Zoe.

ZOE: Goodbye, Doctor. Will we ever meet again?

DOCTOR: Again? Now, Zoe, you and I know, time is relative, isn't it?

DOCTOR: Goodbye, Jamie.

JAMIE: I won't forget you, you know.

DOCTOR: I won't forget you. Don't go blundering into too much trouble, will you?

JAMIE: Oh, you're a fine one to talk.

ZOE: Of course he can. The Doctor's almost as clever as I am.

JAMIE: Doctor, come on, will ye? The whole place is going to blow up.

DOCTOR: Oh, it's quite all right, Jamie. The planet is quite safe. There's just going to be a localised volcanic eruption. It'll only affect the island.

JAMIE: Maybe so, but we happen to be on the island.

DOCTOR: Oh, my word!

DOCTOR: It is too important. I must be sure. Oh dear. What pretty crockery this is. Sad really, isn't it? People spend all their time making nice things, and other people come along and break them.

JAMIE: Have you thought up some clever plan, Doctor?

DOCTOR: Yes, Jamie, I believe I have.

JAMIE: What are you going to do?

DOCTOR: Bung a rock at it.

SONGSTEN: Harsh words are like blunted arrows. It is the truth that makes them sharp.

DOCTOR: Are you happy with us, Victoria?

VICTORIA: Yes, I am. At least, I would be if my father were here.

DOCTOR: Yes, I know, I know.

VICTORIA: I wonder what he would have thought if he could see me now.

DOCTOR: You miss him very much, don't you?

VICTORIA: It's only when I close my eyes. I can still see him standing there, before those horrible Dalek creatures came to the house. He was a very kind man, I shall never forget him. Never.

DOCTOR: No, of course you won't. But, you know, the memory of him won't always be a sad one.

VICTORIA: I think it will. You can't understand, being so ancient.

DOCTOR: Eh?

VICTORIA: I mean old.

DOCTOR: Oh.

VICTORIA: You probably can't remember your family.

DOCTOR: Oh yes, I can when I want to. And that's the point, really. I have to really want to, to bring them back in front of my eyes. The rest of the time they sleep in my mind, and I forget. And so will you. Oh yes, you will. You'll find there's so much else to think about. So remember, our lives are different to anybody else's. That's the exciting thing. There's nobody in the universe can do what we're doing. You must get some sleep and let this poor old man stay awake.

KLIEG: Yes, yes, I can see that, but how did you know in the first place?

DOCTOR: Oh, I use my own special technique.

KLIEG: Oh really, Doctor? And may we know what that is?

DOCTOR: Keeping my eyes open and my mouth shut.

DOCTOR: Do I look strange or bizarre?

JAMIE: Aye. Well maybe I'm just used to you.

TERRALL: Doctor. No doubt you're a keen student of human nature, but some things are better left alone.

DOCTOR: No, Mister Terrall, I am not a student of human nature. I am a professor of a far wider academy, of which human nature is merely a part. All forms of life interest me.