But think of Adam and Eve like an imaginary number, like the square root of minus one: you can never see any concrete proof that it exists, but if you include it in your equations, you can calculate all manner of things that couldn't be imagined without it.

D'you know how embarrassing it is to mention good and evil in a scientific laboratory? Have you any idea? One of the reasons I became a scientist was not to have to think about that kind of thing.

There are some who live by every rule and cling tightly to their rectitude because they fear being swept away by a tempest of passion, and there are others who cling to the rules because they fear that there is no passion there at all, and that if they let go they would simply remain where they are, foolish and unmoved; and they could bear that least of all. Living a life of iron control lets them pretend to themselves that only by the mightiest effort of will can they hold great passions at bay.

One moment several things are possible, the next moment only one happens, and the rest don't exist. Except that other worlds have sprung into being, on which the did happen.

If you can't think of what to write, tough luck; write anyway.

Lyra learns to her great cost that fantasy isn’t enough. She has been lying all her life, telling stories to people, making up fantasies, and suddenly she comes to a point where that’s not enough. All she can do is tell the truth. She tells the truth about her childhood, about the experiences she had in Oxford, and that is what saves her. True experience, not fantasy - reality, not lies - is what saves us in the end.

He's [Jesus] the most fascinating character in history, really - the character who's made more difference to the world than anyone since him. I daresay that Muslims would say Muhammad was that character, but I think Jesus had a sort of 600-year start on him.