This study is the first modern account of the development of philosophy during the Carolingian Renaissance. In the late eighth century, Dr Marenbon argues, theologians were led by their enthusiasm for logic to pose themselves truly philosophical questions. The central themes of ninth-century philosophy - essence, the Aristotelian Categories, the problem of Universals - were to preoccupy thinkers throughout the Middle Ages. The earliest period of medieval philosophy was thus a formative one. This work is based on a fresh study of the manuscript sources. The thoughts of scholars such as Alcuin, Candidus, Fredegisus, Ratramnus of Corbie, John Scottus Eriugena and Heiric of Auxerre is examined in detail and compared with their sources; and a wide variety of evidence is used to throw light on the milieu in which these thinkers flourished. Full critical editions of an important body of early medieval philosophical material, much of it never before published, are included.