Socrates famously claimed that he knew nothing, and that wisdom consisted in awareness of one’s ignorance. In Ignorance, Irony and Knowledge in Plato, Kevin Crotty makes the case for the centrality and fruitfulness of Socratic ignorance throughout Plato’s philosophical career. Knowing that you don’t know is more than a maxim of intellectual humility; Plato shows how it lies at the basis of all the virtues, and inspires dialogue, the best and most characteristic activity of the philosophical life. Far from being simply a lack or deficit, ignorance is a necessary constituent of genuine knowledge. Crotty explores the intricate ironies involved in the paradoxical relationship of ignorance and knowledge. He argues, further, that Plato never abandoned the historical Socrates to pursue his own philosophical agenda. Rather, his philosophical career can be largely understood as a progressive deepening of his appreciation of Socratic ignorance. Crotty presents Plato as a forerunner of the scholarly interest in ignorance that has gathered force in a wide variety of disciplines over the last 20 years.