Everybody is entitled to believe. Churches have exactly the same right to exist as a football club, a trade union or a political party. But if you and I set up the Church of the Fairies of the Garden, then I don't think we should automatically be meeting the queen, be entitled to seats in the House of Lords or get public money for our fairy schools.

Nothing is truly unnatural, because everything that exists, including human intelligence, is a product of nature. If human intelligence can devise ways for the genes from two men to result in a child, their doing so is an entirely natural event.

Nowadays, by contrast, Christianity specialises in soft-focus mood music; its threats of hell, its demand for poverty and chastity, its doctrine that only the few will be saved and the many damned, have been shed, replaced by strummed guitars and saccharine smiles. It has reinvented itself so often, and with such breathtaking hypocrisy, in the interests of retaining its hold on the gullible, that a medieval monk who woke today, like Woody Allen's Sleeper, would not be able to recognise the faith that bears the same name as his own.

Misuse of reason might yet return the world to pre-technological night; plenty of religious zealots hunger for just such a result, and are happy to use the latest technology to effect it.

Religions survive mainly because they brainwash the young.

When I was 14 a chaplain at school gave me a reading list. I read everything and I went back to him with a question: how can you really believe in this stuff?

Science is the outcome of being prepared to live without certainty and therefore a mark of maturity. It embraces doubt and loose ends.