Fifty years ago, William F. Buckley Jr. vowed not to read another book about liberalism until his mother wrote one. Liberalism was riding high then, and Buckley was probably annoyed by its champions’ triumphalist tone. Over the past four decades, things have changed: You can hardly walk around the block today without tripping over a critique of liberalism. There are critiques by wild-eyed Randians, free-market libertarians, neoclassical economists, neo-Burkean conservatives, Catholic integralists, critical race theorists, postmodernists, and, of course, Marxists.