For years, the Washington establishment held up Sally Quinn, the wife of the late Washington Post editor Ben Bradlee, as the society doyenne par excellence and a “serious” reporter. The Great and Good would gather at her mansion to bat around the issues of the day. Much talk of a sinister religiosity afoot in the land would ensue. But it turns out that Quinn, when not passing around drinks and appetizers to these self-proclaimed rationalists, was in the back playing with her tarot cards and concocting hexes for her enemies. In her new “spiritual memoir,” Finding Magic, Quinn discloses her...