Perhaps this workload shortened Lewis's life. Other obligations were tougher: during 17 years' work on his volume of the Oxford History of English Literature, he called it 'the O Hell'. One duty was a delight: he loved Magdalene College, Cambridge, where he was professor from 1954 he imagined haunting it benevolently as a 'bald and bulky spectre'. He juggled many roles - reading and writing prodigiously, chairing meetings, astutely criticising the books of friends, comforting strangers and thanking children for Narnian letters and drawings. So did his illiberal but compassionate views on morality. His disagreement with modernism arose from hard thinking. are almost out of sight of his castle.' His bereavement in 1960 is all the sadder because the more one reads his letters, the less easy it is to dismiss Lewis as pugnacious or intolerant. 'Dare one hope for a second resurrection?' he asks, or, veering characteristically from Bible to fairy tale: 'It is like being recaptured by the giant when you. X-rays reveal a redoubled assault by the cancer. It is 'almost miraculous', he says, then rebukes his hopes. While Joy's bones regrow, osteoporosis attacks his own. His fatigue reminds him of the front line. The sense of springtime in autumn is poignant: 'You would hardly believe how much happiness, not to say gaiety, we have - a honeymoon on a sinking ship.' They are married in hospital by a priest. But it was Joy's diagnosis with cancer in October 1956 that transformed Lewis. Her sons, both under 10, delighted and exhausted him. Joy, described by Lewis as 'our queer, Jewish, ex-Communist, American convert', arrived in 1952 as a fan leant on him through her divorce and then accepted his offer of a register office marriage in 1956 so she could stay in Britain. The woman Lewis truly hoped to meet in the hereafter was the poet Joy Gresham, whom he loved but outlived in extraordinary circumstances that were mythologised in the movie Shadowlands. He gives sympathy and money until, terminally ill, he signs off implausibly: 'It will be fun when we at last meet.' One, a widow from Virginia called Mary Willis Shelburne, elicited dozens of letters from Lewis over her anxieties about pets, money and dental surgery. By the time she died in 1951, a gaggle of unhappy female penpals depended on him for advice. Lewis sometimes referred to her as his own mother.

Since 1918 his life had been dominated by Janie Moore, the mother of a comrade killed in the trenches.

Yet a man who thrived on male bonhomie spent much energy caring for women in need. With rooms until 1954 above the deer park of Magdalen College, Oxford, and a big house shared with his brother, surrounded by books and friends such as Tolkien, you might think Lewis had it made. The letters of his last 14 years reveal a further growth of Lewis's imagination: a costly sympathy, worn like a hair shirt.

Cs lewis letters from the devil