We have to understand how the extremists got the way they are. Without that kind of understanding, we'd never really get to know them. I put in nothing about their childhoods. But what I have put in is stuff about the weird symbiotic relationship between us and them.

Sometimes labeling is only useful, like with OCD. Once you're labeled you can be treated. On other occasions labeling leads to tyranny, like with childhood bipolar disorder in the U.S.

I think if somebody is so set in their ways about what they feel about something - and you get this a lot in academia, of course, and also different sorts of journalism too - you're going to sweep under the carpet the facts that don't suit your thesis. And I think that happens quite a lot in the courtroom, for instance.

Trying to prove you’re not a psychopath is even harder than trying to prove you’re not mentally ill,’ said Tony.

There is no evidence that we've been placed on this planet to be especially happy or especially normal. And in fact our unhappiness and our strangeness, our anxieties and compulsions, those least fashionable aspects of our personalities, are quite often what lead us to do rather interesting things.

Obviously, I like to write stories that are page-turners. But I always try my very, very hardest to be as factually true as possible.

I wasn't in any way a kind of soothsayer or not surprised when Sept. 11 happened. I was absolutely shocked.