The Unity of Oneness and Plurality in Plato's Theaetetus carefully engages the dialogue’s arguments while also wrestling with the philosophical problems the dialogue explores. The result is both extraordinary scholarship and a profound philosophical reflection on the possibility of knowledge. What sets this study apart from others are Bloom’s appreciation of the reflexivity inherent in an inquiry that seeks to know what knowledge is and his understanding of Plato’s use of irony as a positive tool. Bloom embraces the dialogue’s paradoxes and, in consequence, is able to see in it a unity and coherence that has escaped other readers. This book is an extraordinary achievement.