- The Development of the Idea of History in Antiquity. Montreal: McGill-Queens University Press, 1982; reprinted 2003; published as e-book 2008. ISBN 9780773563971
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- Study Guide for the logic textbook Thinking Logically (1988).
- Editor, Plato’s Dialogues: New Studies and Interpretations. Savage, MD: Rowman and Littlefield, 1993; published as e-book 2010..
- Editor, Who Speaks For Plato? Studies in Platonic Anonymity. Savage, MD: Rowman and Littlefield, 2000; published as e-book 2009. ISBN-10: 0847692183
- Plato: A Guide for the Perplexed. London: Continuum, 2007; reprinted 2009, 2010; published as e-book, 2009. ISBN-10: 0826491766
- Editor, The Continuum Companion to Plato. London: Continuum International Publishing, 2012; published as e-book 2013. ISBN: 9780826491770
- Editor for Ancient Philosophy, Columbia History of Western Philosophy ISBN-13: 9780231101295
- Book Review Editor, Journal of the History of Philosophy (1990 – 1997), Editor, Journal of the History of Philosophy (1998 – 2003)