Candide is one of those books I read when I was young and that I come back to regularly.

Theatre within theatre, when characters sees themselves on stage, always raises philosophical questions of choice and free will.

I have adapted the whole book [Candid] into tweets of 140 characters, and these are being sent out daily, at the rate of eight tweets per day .

Even within single sentences, there are sudden changes of register. And when the travellers go to Venice, they see a play by Voltaire! This is a novel [Candid] which has narratives within narratives, such as when Cunégonde recounts her story.

Optimism and happiness are not the same thing, but they are becoming interchangeable, and it seemed to me that Voltaire's Candide gave me a way into something important happening in modern-day culture.

It's a book that makes me laugh and think - it would be very hard to like someone who didn't enjoy Candide!

Twenty years ago, when you bumped into someone and asked how they were, they would say, 'Mustn't grumble' or 'Getting by': now they feel obliged to say 'Just great!'. In both cases, the reply is just a social nicety, but the framework has changed, it's as if it's become a social duty to express happiness.