Alexander the Corrector, by Julia Keay

The Bible itself is a volume needing an editor's pruning-implement but, at 2.3 million words, the Concordance to the Good Book is three times its length. Apart from "a", "the", "of", "to" and "with", and most "ands", "buts" and "froms", the Concordance lists the occurrences of every single word.

There are 35 references to "honey", 94 to "wine". All the "alls" are quoted, including "above all" and "all ye". The entry for "synagogue" includes a 4,000-word article on places of worship.

Just reading the Concordance would drive most of us round the twist. No wonder the individual who compiled it, Alexander Cruden, was locked up several times in an asylum. After his final release, he appointed himself "Corrector of the People" and went around "correcting" people for swearing or failing to observe the Sabbath.

In this excellent biography, Julia Keay tells the extraordinary story of the Scottish scholar who, on the point of being ordained, was incarcerated on grounds of insanity. Cruden's reputation for madness survives in, for example, his entry in my copy of the Encyclopaedia Britannica. However, Keay presents evidence that he was not mad, but put away by a powerful Aberdeen family to silence him. He had discovered that a girl whom he was unsuccessfully courting was pregnant by her own brother. Later, the incestuous lady set herself up as the "wife" of another brother.

The poor would-be clergyman, now with a psychiatric record, was defrocked before he had even been frocked. He had to make ends meet in London as a proof-reader. Here Cruden turned to his Plan B for serving God: his Concordance, which would assist the study of the Bible. After 12 years of moonlighting, he produced his extremely magnum opus in 1737.

His triumph was ruined, again by a woman who did not want his affection. This time it was another suitor of a well-off widow who, learning of Cruden's record, declared him insane and dumped him in a private asylum. Alexander, still in chains, managed to clamber over the wall. Four years later he may have been in Bethlem hospital (aka Bedlam) with a nervous breakdown. He was certainly locked up again 10 years later, after a fight with some men who were swearing. His sister committed him; the two siblings did not get on.

Soon released, he became a fully-fledged eccentric, declaring himself a "Corrector' not just of proofs but of men and women. He failed in his plans to become a knight, an MP and the husband of yet another unwilling lady, but was honoured for the Concordance. It finally began to sell and, a quarter of a millennium later, is still in print.

Like The Surgeon of Crowthorne by Simon Winchester (whose endorsement graces the front cover), this is an enthralling tale of a batty pedant. I found myself wishing that Julia Keay had included more material about the Concordance itself - and that's a miracle.