And that controversy leads to another one. Does Darwinian selection take place at the level only of individuals, or of groups as well? As Mr Wade makes clear, the notion of religion as an “adaptive” phenomenon makes better sense if one accepts the idea of group selection. Groups which practised religion effectively and enjoyed its benefits were likely to prevail over those which lacked these advantages.

All religion is concerned in varying degrees with metaphysical ideas, moral norms and mystical experience. But in the great religions, the moral and the mystical have often been in tension. The more a religion stresses ecstasy, the less it seems hidebound by rules—especially rules of public behaviour, as opposed to purely religious norms. And religious movements (from the “Deuteronomists” of ancient Israel to the English Puritans) that emphasise moral norms tend to eschew the ecstatic.

Max Weber, one of the fathers of religious sociology, contrasted the transcendental feelings enjoyed by Catholic mass-goers with the Protestant obsession with behaviour. In Imperial Russia, Peter the Great tried to pull the Russian Orthodox church from the former extreme to the latter: to curb its love of rite and mystery and make it more of a moral agency like the Lutheran churches of northern Europe. He failed. Russians liked things mystical, and they didn’t like being told what to do.