What is the difference between lying and speaking insincerely? Does misleading count as lying? And precisely what sort of indifference to truth does “bullshitting” involve? In Lying and Insincerity (Oxford University Press, £50; Tablet price £45), Andreas Stokke analyses such questions exhaustively, using snatches of dialogue to illustrate his points. Because he focuses, and in such a technical way, on the language of insincerity, rather than its psychological and moral aspects, the general reader may find this book more casuistical than illuminating.