“What is philosophy?” is a question that admits many answers. One of the simplest—and the best—was suggested by the philosopher John Campbell: “Thinking in slow motion.” But, for most people, slow motion is only appealing in small doses. A whole movie in slow-mo would be one for the art gallery, not the multiplex. This is the problem that faces those who want to write about philosophy for a broad readership: a certain amount of fast-forward is needed, but if you go too fast you’ll stop doing philosophy altogether. John D Caputo’s entertaining investigation into the nature of truth gets the balance right. His project is to show how postmodernism can help us think through contemporary debates about religion, relativism and the legacy of the Enlightenment. Rather than dividing the world into strict categories such as the rational and irrational, Caputo’s postmodern approach tries to widen our understanding of truth. He is not a naive relativist, however. “I am not arguing against the truth of propositions,” he says. “I am arguing that truth cannot be confined to propositions.” This means taking seriously the truths one encounters in novels, say, as well as religious narratives. As this last idea suggests, there is plenty in Truth to annoy Richard Dawkins, as well as many contemporary analytic philosophers—but the book is better off for its boldness. Rather than pre-empting every counter-attack, Caputo sets out his case confidently, enlisting Nietzsche, Kierkegaard and Derrida as his allies. (His explanation of Derrida’s thought is one of the clearest that I’ve read.) This book does not claim to be the final word on truth—indeed Caputo believes the quest for an ultimate and unchanging definition of truth is doomed to failure—but it might be the starting point for a more sophisticated discussion.