BA 1992; BPhil 1994; DPhil 1997, all at Oxford. Post-doctoral Fellow of the British Academy (1997-2000); Michael Cohen Fellow and Tutor in Philosophy at Exeter College, Oxford (2001-9). Joined the Faculty in Fall 2009. He has published a monograph, "On Location: Aristotle's Concept of Place" (Oxford: Oxford University Press, 2002), and contributed two chapters to the Cambridge Companion to Galen (Cambridge: CUP, 2008). Other publications include contributions to two volumes of the Symposium Aristotelicum, one on De Motu Animalium (OUP, 2020), the other on Physics I (2019), and to the volume of the Symposium Hellenisticum on Dialectic (2019). In 2025, his and Jonathan Barnes' edition of Galen's Institutio Logica, with introduction, translation, and commentary will come out with OUP. He was Director of the Princeton Program in Classical Philosophy (2014-22) before becoming Chair of the Department of Philosophy in 2022. He publishes mainly on logic, physics, geometry, and epistemology in Plato, Aristotle, and the Hellenistic period, but is interested in all aspects of ancient philosophy.