Research interestsHas interests in a broad range of subjects within ancient Greek and Roman philosophy. Author (with G.S. Kirk and J.E. Raven) of The Presocratic Philosophers (Cambridge U.P., 1983 [2nd edn.]), The Stoic Idea of the City (Chicago U.P., 1999 [expanded edn.]), Saving the City (Routledge, 1999), and Plato: Political Philosophy (Oxford U.P., 2006). Co-editor of The Cambridge History of Hellenistic Philosophy (Cambridge U.P., 1999), and the Cambridge History of Greek and Roman Political Thought (Cambridge U.P., 2000). Editor of Aristotle, Plato and Pythagoreanism in the First Century B.C. (Cambridge U.P., 2013). Currently working mostly on Plato's Laws and on Cicero's philosophical writings.