‘I do not believe in Belief.’ Those memorably aphoristic opening words of E.M. Forster’s essay ‘What I Believe’ are more problematical than they care to admit. For one thing, they seem to suggest that the concept refuted by Forster as a noun is perfectly acceptable to him as a verb: he goes on to say that he believes in ‘an aristocracy of the sensitive, the considerate and the plucky’. But then – to get the grammar out of the way first – ‘to believe’ is a slippery sort of verb. In sentences such as ‘I believe the sky is blue today’ or ‘I believe the train leaves at eleven-thirty’, it’s usually possible to substitute ‘I know’ or ‘I think’. However, the little preposition makes a big difference: in ‘I believe in God’ or ‘I believe in whisky as the cure for a cold’, the meaning is ‘I have faith in’. More confusingly still, when someone says ‘I believe so’, they’re implying ‘but I’m not at all sure’. Belief and doubt are joined inextricably and you can’t, as the song says, have one without the other.

In fact, Forster evades the more perplexing of his two implied questions, which isn’t ‘What do I believe in?’ but ‘What does "believe in" mean?’ People who grow up in places where faith is taken for granted – such as Richard Holloway, the former Bishop of Edinburgh and author of Leaving Alexandria – evidently have an intuitive sense of this meaning and are likely ...