Rose: 'If you are an alien, how come you sound like you're from the north?' Doctor: 'Lots of planets have a north!

My problem is that the audience is more fiction-literate than ever. In Shakespeare's day, you probably expected to see a play once or twice in your life; today you experience four or five different kinds of fiction every day. So staying ahead of the audience is impossible.

When man invented fire, he didn't say, "Hey, let's cook." He said, "Great, now we can see naked bottoms in the dark.

What's the point of being a grown-up if you don't get to be immature?

You can be as beautiful and charming as you'd like, but if you're not terrific at acting, it will mean nothing on the screen.

Don't play games with me! You just killed someone I like, that is not a safe place to stand! I'm the Doctor, and you're in the biggest library in the Universe. Look me up.

I know this is going to sound very self-serving, and I apologize for it, but if you can write comedy, you can pretty much write anything, because it's the hardest. It's the most technically demanding, the most precisely evaluated form of writing. People know if it works or not. There's a big button marked 'fail,' and that's when nobody laughs.