Every episode [in a TV series] is a challenge, and what's challenging in most episodes is the monster. You're always a heartbeat from the monster looking ridiculous. You really have to work so hard to make them not look like ridiculous when they turn up on the set.

Amy: "Can I come?" Doctor: "Not safe in here, not yet. Five minutes. Give me five minutes and I'll be right back." Amy: "People always say that." Doctor: "Am I people?...Do I even look like people?...Trust me, I'm the Doctor.

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

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.

When writing comedy, you have to have the confidence to believe that there is only one type of relationship in the world, and we are all having it, that all men behave in the same way and so do all women.

Sherlock Holmes becomes more human and more adept at fitting in with a lot of people, but he remains separate from the human race because he finds that a better place to observe that from. He stays on the mountain top because there, he can see clearly.

Madness is just what a genius looks like to a tiny mind.