It's known that stress gives rise to disease. It's also known that many diseases, especially stress-related diseases, can be cured by placebos - pills that have no medicinal effect, but people think they do, and so they do.

Scientists can have their judgment clouded by their professional aspirations. And the pure truth of faith, which you can think of as this clear spiritual water, is poured into rusty vessels called human beings, and so sometimes the benevolent principles of faith can get distorted as positions are hardened.

Religious people are atheists about all other gods, atheists only take it one god further.

We think we know that chimpanzees are higher animals and earthworms are lower, we think we've always known what that means, and we think evolution makes it even clearer. But it doesn't. It is by no means clear that it means anything at all. Or if it means anything, it means so many different things to be misleading, even pernicious.

If God wanted to create life and create humans, it would be slightly odd that he should choose the extraordinarily roundabout way of waiting for 10 billion years before life got started and then waiting for another 4 billion years until you got human beings capable of worshipping and sinning and all the other things religious people are interested in.

Blindness to suffering is an inherent consequence of natural selection. Nature is neither kind nor cruel but indifferent.

The river of my title is a river of DNA, a river of information, not a river of bones and tissues