Writing the history of the present is no easy task. For every influential idea, there are dozens of others that might explain how we got here – and “here” is an ongoing situation. But at the moment, a number of historians and commentators can be heard wondering whether the era of liberalism is drawing to an end : whether it even failed because it succeeded (as the theorist Patrick Deneen puts it), which is to say that its stress on individual desire came to erode the basis for its own foundation.  It’s true that liberalism is under long-term attack from both the Left and the Right. For Marxists, it’s just a bourgeois cover-story papering over exploitation and violence with a thin layer of law; for social conservatives, it’s a degenerate free-for-all that destroys families and turns people away from God.…