Richard McKirahan is E.C. Norton Professor of Classics and Professor of Philosophy, Pomona College, USA. He has published widely on ancient philosophy and science, including Simplicius: On Aristotle Physics 8.6-10 (Bloomsbury, 2001), Philoponus: On Aristotle Posterior Analytics 1.1-8 (Bloomsbury, 2008) and Philoponus: On Aristotle Posterior Analytics 1.9-18 (Bloomsbury, 2012).