Professor Mann joined the Columbia Philosophy Department in 1992. His research interests include: theories of argumentation (i.e. logic and rhetoric, broadly construed), beginning with Socrates and Plato; the history of central metaphysical contrasts—e.g. corporeal/incorporeal, composite/simple, whole/part, matter/form, object/property, potentiality /actuality—throughout antiquity and the middle ages; and within ethics, treatments of the relation between rational and non-rational motivation, and accounts of freedom (e.g. those of Epictetus and Plotinus) which do not require that an agent be able to act differently (from how s/he actually does act) in order to count as free. He has also worked on English and German Romanticism (especially, Wordsworth and Hölderlin); the reception of classical antiquity in 19th century Britain and Germany; and the historiography of philosophy.
He is the author of The Discovery of Things: Aristotle’s Categories and Their Context (2000); and he recently co-edited, with James Allen, Eyjólfur Emilsson, and Benjamin Morison, Oxford Studies in Ancient Philosophy, vol. 40: Essays in Memory of Michael Frede (2011).