“The historian’s business is to know the past, not to know the future,” R. G. Collingwood insisted, “and whenever historians claim to be able to determine the future in advance of its happening, we may know with certainty that something has gone wrong with their fundamental conception of history.”12 Or, as Tom Stoppard’s heroine Thomasina puts it in his play Arcadia: “You cannot stir things apart.”13
