Books are not, in fact, the most important vehicle for scholarship in this area, as the absence of scholars like Myles Burnyeat, Alan Code, G.E.L. Owen, and Gisela Striker, among others, would suggest. But there are some very important and influential books, as the list shows. I have excluded translations with commentaries on important ancient texts, and focused on monographs. (I also exclude Nussbaum’s The Fragility of Goodness, which appeared on the ethics list, but it could also have appeared here.) I list only books with at least 700 citations. As always, email me about omissions or corrections.

1. W.K.C. Guthrie, A History of Greek Philosophy, volume I, 6,000
2. Martha Nussbaum, The Therapy of Desire: Theory and Practice in Hellenistic Ethics, 4,000
3. Julia Annas, The Morality of Happiness, 3,400
4. Gregory Vlastos, Socrates, Ironist and Moral Philosopher, 2,400
5. Jonathan Barnes, The Presocratic Philosophers, 2,300
6. Terence Irwin, Aristotle’s First Principles, 1,900
7. Sarah Broadie, Ethics with Aristotle, 1,800
8. Charles Kahn, Plato and the Socratic Dialogue, 1,800
9. Terence Irwin, Plato’s Ethics, 1,600
10. Terence Irwin, Plato’s Moral Theory: The Early and Middle Dialogues, 1,400
11. Richard Sorabji, Animal Minds and Human Morals: The Origins of the Western Debate, 1,400
12. Richard Sorabji, Emotion and Peace of Mind: From Stoic Agitation to Christian Temptation, 1,400
13. Jonathan Lear, Aristotle: The Desire to Understand, 1,300
14. John M. Cooper, Reason and Human Good in Aristotle, 1,300
15. W.K.C. Guthrie, The Sophists, 1,200
16. Brad Inwood, Ethics and Human Action in Early Stoicism, 1,200
17. Charles Kahn, Anaximander and the Origins of Greek Cosmology, 1,100
18. Susanne Bobzien, Determinism and Freedom in Stoic Philosophy, 1,100
19. Gregory Vlastos, Platonic Studies, 1,000
20. C.D.C. Reeve, Philosopher-Kings: The Argument of Plato’s Republic, 900
21. Richard Sorabji, Necessity, Cause and Blame: Perspectives on Aristotle’s Theory, 900
22. Thomas Brickhouse & Nicholas Smith, Plato’s Socrates, 800
23. John M. Cooper, Reason and Emotion: Essays on Ancient Moral Psychology and Ethical Theory, 800
24. Michael Frede, Essays in Ancient Philosophy, 800
25. Julia Annas, Hellenistic Philosophy of Mind, 700
26. Richard Kraut, Aristotle: Political Philosophy, 700