Resumo

GAMBOA, Lydia Deni. How can we have clear or unclear perceptions of an object?: William of Ockham and Walter Chatton on the degree of perfection of mental acts. Tópicos (México) [online]. 2015, n.49, pp.09-26. ISSN 0188-6649.

During the fourteenth century there were two main theories concerning the intension and remission of qualities, understood as accidental forms. The supporters of the first theory considered that a quality increases or decreases due to the addition or subtraction of its own parts, whereas the defenders of the second one considered that a quality increases or decreases due to the successive substitution of a previous form with a new one. Ockham advocated the first account regarding mental states understood as qualities. Chatton advocated in his first writings both theories but, in his mature writings, he defended only the second one. Ockham and Chatton's theories are based on different views concerning the nature of change. In addition, both theories involve different mechanisms regulating the greater or lesser perfection of a mental state.

Palavras-chave : William of Ockham; Walter Chatton; mental states; intension and remission; philosophy of mind.