Gregory Vlastos (/ˈvlæstoʊs/; Greek: Γρηγόριος Βλαστός; July 27, 1907 – October 12, 1991) was a preeminent scholar of ancient philosophy, and author of many works on Plato and Socrates. He transformed the analysis of classical philosophy by applying techniques of modern analytic philosophy to restate and evaluate the views of Socrates and Plato.^[1]

Vlastos was born in Istanbul, to a Scottish mother and a Greek father, where he received a Bachelor of Arts from Robert College before moving to Harvard University where he received a PhD in 1931. After teaching for several years at Queen's University in Kingston, Ontario, Canada, he moved to Cornell University in 1948. He was Stuart Professor of Philosophy at Princeton University between 1955 and 1976, and then Mills Professor of Philosophy at University of California, Berkeley until 1987. He received a MacArthur Foundation Fellowship in 1990.^[1] He was twice awarded a Guggenheim Fellowship,^[2] was a fellow of the American Academy of Arts and Sciences, a corresponding fellow of the British Academy, and a member of the American Philosophical Society.^[3] In 1988 he gave the British Academy's Master-Mind Lecture.^[4] Vlastos died in 1991, before finishing a new compilation of essays on Socratic philosophy.

He is credited with bringing about a renaissance of interest in Plato among philosophers throughout the world.^[3] Many of Vlastos' students have become important scholars of ancient philosophy, including Terence Irwin, Richard Kraut, Paul Woodruff, and Alexander Nehamas.

In his work The Philosophy of Socrates: a Collection of Critical Essays (UNDP 1971), Vlastos advanced the idea "that one can identify in certain Platonic dialogues a philosophical method and a collection of philosophical theses which may properly be attributed to Socrates."^[5] He suggested a plausible modern analytic framework for Socratic philosophy as a pursuit distinct from Platonic philosophy. The dialogues of Plato’s Socratic period, called "elenctic dialogues" for Socrates’s preferred method of questioning, are Apology, Charmides, Crito, Euthyphro, Gorgias, Hippias Minor, Ion, Laches, Protagoras and book 1 of the Republic.^[6] The idea remains controversial^[7][8] and those who agree with his position are referred to as Vlastosians.^[5]

• Christian Faith and Democracy, Association Press, 1939.
• Platonic Studies, Princeton University Press, 1973, ISBN 978-0-691-07162-6 ISBN 0691071624; 1981 2nd edition, pbk
• Socrates, Ironist and Moral Philosopher, Cornell University Press, 1991, ISBN 978-0-8014-9787-2 ISBN 0801497876^[9]
• Socratic Studies, Cambridge University Press, 1994, ISBN 978-0-521-44735-5 ISBN 0521447356; 1995 pbk reprint
• Studies in Greek Philosophy Volume I: the Presocratics, Princeton University Press, 1995, ISBN 978-0-691-03310-5 ISBN 0691033102
• Studies in Greek Philosophy; Volume II: Socrates, Plato, and Their Tradition, Princeton University Press, 1995, ISBN 978-0-691-03311-2 ISBN 0691033110
• Plato's Universe, Parmenides Publishing, 2005, ISBN 978-1-930972-13-1 ISBN 193097213X

• Harold F. Cherniss, for the Cherniss-Vlastos critique of the Tübingen School
• Vlastos