This is a strange book, to put it mildly. Its oddness begins with the title, for there is no sense in which the four persons on whom Wolfram Eilenberger concentrates were magicians, and I don’t know what a metaphorical sense of ‘magician’ would be. However, this book, which is Eilenberger’s ninth, was a bestseller in Germany and is being translated into more than twenty languages. He has written on Nostradamus, so clearly his taste inclines towards the esoteric. In Time of the Magicians, he takes four extremely disparate figures from the years between the two world wars, all of them German speakers, three of them – Martin Heidegger, Ernst Cassirer and Walter Benjamin – actually German and the fourth, Ludwig Wittgenstein, Austrian. The book traces their lives after the First World War, in which Wittgenstein was the only one to have participated, bravely and with possibly suicidal intent, until he was taken prisoner.