Engraving by Abraham Bosse. Photo by Stefano Bianchetti/Corbis via Getty Images “Post-liberalism” is the inescapable watchword of our times. Turn to the comment section of any major English-language periodical, and chances are you will find at least one column, feature or review devoted to this phenomenon. Usually, the pieces in question concern a small coterie of mainly American and mainly Catholic writers who argue that many of today’s political, economic and cultural crises trace back to liberal ideology. Atomisation, inequality, environmental degradation, identity warfare: these and related troubles, the post-liberals insist, aren’t distortions of the original liberal ideal, but its...