ABSTRACT
Philosophy in the 20th century began and ended with an obsession with the problems of consciousness. But the specific problems discussed at each end of the century were very different, and reflection on how these differences developed will illuminate not just the authors’ understanding of the history of philosophy of consciousness, but also the authors’ understanding of consciousness itself. The phenomenological movement he initiated often claimed its inspiration in Franz Brentano's classification of all mental phenomena as intentional. Whereas Moore and Husserl saw consciousness and thought as intertwined, it is tempting to see Lewis's creation of his conception of qualia as a first step in the separation of consciousness from intentionality which became orthodox in late 20th-century analytic philosophy. The idea that consciousness is something inexpressible, indefinable, inefficacious, additional and separable from the rest of mental life — from judgements, concepts, beliefs, thoughts and so on — came to be the central theme of later discussions of consciousness.
