Mental Language
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. This book examines the background of Ockham's innovation by tracing the history of the mental language theme in ancient and medieval thought. It shows the various contexts in which the idea was developed, the different uses it was put to, and the networks through which it was transmitted. Two ancient traditions are identified as relevant: one philosophical, stemming from Plato and Aristotle, which led to the emergence of a technical notion of ‘internal discourse’ in later Greek philosophy; and the other theological, rooted in the Fathers of the Christian Church and reaching its apogee in Augustine in the fifth century A.D. 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. And it finally 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.