William of Ockham (c. 1287-1347) is known to be one of the major figures of the late Middle Ages. The scope and significance of his doctrine of human thought, however, has been a controversial issue among scholars in the last decade, and this book presents a full discussion of recent developments. Claude Panaccio proposes a richly documented and entirely original reinterpretation of Ockham's theory of concepts as a coherent blend of representationalism, conceptual atomism, and non reductionist nominalism, stressing in the process its special interest for current discussions in philosophy of mind and cognitive sciences.

The notion that human thought is structured like a language, with a precise syntax and semantics, has been pivotal in recent philosophy of mind. Yet it is not a new idea: it was systematically explored in the fourteenth century by William of Ockham and became central in late medieval philosophy. Mental Language examines the background of Ockham's innovation by tracing the history of the mental language theme in ancient and medieval thought. Panaccio identifies two important traditions: one philosophical, stemming from Plato and Aristotle, and the other theological, rooted in the Fathers of the Christian Church. The study then focuses on the merging of the two traditions in the Middle Ages, as they gave rise to detailed discussions over the structure of human thought and its relations with signs and language. Ultimately, Panaccio stresses the originality and significance of Ockham's doctrine of the oratio mentalis (mental discourse) and the strong impression it made upon his immediate successors.

William of Ockham (1287-1347) is oft considered the most important nominalist thinker of the Middle Ages. Nominalism, a metaphysical view that has had adherents throughout the history of Western philosophy, largely denies the extramental existence of universals and abstract objects by reducing them to linguistic or mental items. Philosopher Claude Panaccio views Ockham's genre of nominalism as consisting of three theses: that there are no universals in the external world, no relations, and no quantities considered as distinct entities. Claude Panaccio here displays the outlines of a rich and carefully crafted nominalist system that is still of great philosophical interest today. In so doing, the volume situates Ockham's thought with respect to several salient contemporary debates in philosophy. Ockham's Nominalism provides a unique systematic introduction to his thought about universals, relations, and quantities, situating his doctrines on these matters with respect to today's debates in metaphysics, philosophy of mind, philosophy of language, and epistemology.