Among the astonishing variety of sources mentioned in Martin Jay's new book on lying in politics the reader will find ancient Greek philosophical dialogues, pamphlet controversies between eighteenth-century philosophers, post-structural literary theories and, resting easily among the likes of these, a familiar old joke. “How can you tell when a politician is lying?” Jay asks. “He moves his lips” is the answer my grandfather used to give, and that is the punch-line that Jay recounts here. But my grandfather told the joke as part of a syllogism whose unstated premise was “lying is bad” and whose common-sense conclusion was that politics is corrupt. Jay is not satisfied with that conclusion. His book, The Virtues of Mendacity: On Lying in Politics, puts forward a very different argument: He assumes that politics is worthwhile, suggests that it is unavoidably linked to lying, and concludes that lying must not be as bad as we think it is. There are a host of complications and caveats, so many that one could spend a whole review admiring the virtuosity involved in constructing such a rich pastiche of historical episodes and texts touching on mendacity. But the frisson that the book provokes comes almost entirely from its willingness to flirt with the endorsement of vice, so any serious engagement with it cannot avoid responding in some way to that flirtation.