Perhaps the most influential Parisian philosopher of the fourteenth century, John Buridan did much to shape the way philosophy was done not only during his own lifetime, but throughout the later scholastic and early modern periods. He spent his entire career as a teaching master in the arts faculty at the University of Paris, lecturing on logic and the works of Aristotle and producing commentaries and independent treatises on logic, metaphysics, natural philosophy, and ethics. His most famous work is the Summulae de dialectica (Compendium of Dialectic), a text of astonishing breadth and originality aimed at updating the older tradition of Aristotelian logic using the newer, terminist logic of ‘moderns’ such as Peter of Spain and William of Ockham. Buridan applied these analytical techniques so successfully in his metaphysics, natural philosophy, and ethics that, for many of his successors, they came to be identified with the method of philosophy, understood as a secular practice, i.e., as distinct from theology.