Sam Leith, literary editor of Spectator magazine, recently put author Benjamin Moser on the spot. ‘Do you think her work will last?’ he asked, referring to the writings of Susan Sontag, whose biography Moser had not long finished. ‘And if so, which of it?’ Moser dissembled bravely. ‘Well, I hope so ...’

Yet was it dissembling? Or even brave, for that matter? Sontag’s oeuvre need not survive for Moser’s book – seven years in the making – to be a success, which it undoubtedly is. But, as one instance of monstrous behaviour gives way to another, we are left hoping that the work does survive, that it is forever recognised as a milestone in twentieth-century intellectual history, that the words exculpate the person. Otherwise, what’s the point?