The aim of this project is to produce an encyclopedia that is complete and covers all areas of medieval philosophy or rather all areas of philosophy between 500 and 1500. The encyclopedia will thus include parts of renaissance philosophy as well. Research on medieval philosophy has advanced greatly in the last thirty years, but there is no encyclopedia that scholars can turn to and that summarizes current research. This encyclopedia is primarily meant for scholars, but it can also be used by others who are interested in medieval philosophy. The encyclopedia contains entries on medieval philosophers, and, in addition, it contains entries on areas in medieval philosophy and on specific, important terms and concepts in these areas. It will thus present a comprehensive overview of medieval philosophy and it will give details and analyses of particular theories. Take logic for example. There will of course be an entry on medieval logic in general, written by an expert, but there will also be other entries on supposition theory, syllogisms, consequences, etc., which will considerably deepen the discussion on this particular topic. The encyclopedia will contain entries on the teaching of philosophy, the career of philosophers and the place of philosophy within universities as well. It will thus also present social and contextual aspects of philosophy in the Middle Ages.