When Dickens wanted to buy a house in 1837, he wrote to Richard Bentley, who had started the magazine in which Oliver Twist was to be serialised, saying he had mentioned his name ‘among those of other references, to testify to my being “sober and honest”.’

Some people seem to think it was this kind of reference that was meant by the remarkable president of Magdalen College, Martin Routh, who stayed in office until his death aged 99 in 1854, shortly before which, on being asked what advice he would give to a young don, said: ‘You will find it a...