Next time that somebody tells you something is true, why not say to them: 'What kind of evidence is there for that?' And if they can't give you a good answer, I hope you'll think very carefully before you believe a word they say.

The feature of living matter that most demands explanation is that it is almost unimaginably complicated in directions that convey a powerful illusion of deliberate design.

Bush and bin Laden are really on the same side: the side of faith and violence against the side of reason and discussion. Both have implacable faith that they are right and the other is evil. Each believes that when he dies he is going to heaven. Each believes that if he could kill the other, his path to paradise in the next world would be even swifter. The delusional "next world" is welcome to both of them. This world would be a much better place without either of them.

We are machines built by DNA whose purpose is to make more copies of the same DNA. ... This is exactly what we are for. We are machines for propagating DNA, and the propagation of DNA is a self-sustaining process. It is every living object's sole reason for living.

Five per cent vision is better than no vision at all. Five per cent hearing is better than no hearing at all. Five per cent flight efficiency is better than no flight at all. It is thoroughly believable that every organ or apparatus that we actually see is the product of a smooth trajectory through animal space, a trajectory in which every intermediate stage assisted survival and reproduction.

You don't believe that the Earth is round only if you're an astronaut. You don't believe Napoleon existed only if you're a historian. You believe these things because they're facts, proved by evidence.

I am very hostile to religion because it is enormously dominant, especially in American life. And I don't buy the argument that, well, it's harmless. I think it is harmful, partly because I care passionately about what's true.