I think that [Paul] Bloom's approach - and others who take it - is not so much that there is a precise genetic basis to faith. But there is a genetic basis to a psychological predisposition that manifests itself as faith and religion under the right conditions.

The physicist's problem is the problem of ultimate origins and ultimate natural laws. The biologist's problem is the problem of complexity.

Evolution could so easily be disproved if just a single fossil turned up in the wrong date order. Evolution has passed this test with flying colours.

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.

Bertrand Russell used a hypothetical teapot in orbit about Mars for the same didactic purpose. You have to be agnostic about the teapot, but that doesn't mean you treat the likelihood of its existence as being on all fours with its non-existence.

Some sort of belief in all-powerful supernatural beings is common, if not universal. A tendency to obey authority, perhaps especially in children, a tendency to believe what you're told, a tendency to fear your own death, a tendency to wish to see your loved ones who have died, to wish to see them again, a wish to understand where you came from, where the world came from, all these psychological predispositions, under the right cultural conditions, tend to lead to people believing in things for which there is no evidence.

Faith is belief without evidence and reason; coincidentally that's also the definition of delusion.