ABSTRACT
Throughout the modern period, the idea that minds and mental events constitute a logically distinct category from that of material things and physical events has never failed to occupy a central place in philosophical discussion. In the philosophy of R. Descartes, the dualism of mind and matter was expounded in a manner that has been complicated in numerous ways by his successors but with a clarity and definiteness that has never been improved on. Dualism has had to face three main kinds of objection: logical, causal and epistemological. The logical difficulty is that of accounting for the unity of the mind. Behaviourism, as a philosophy of mind rather than as a methodological self-denying ordinance of psychologists, in its primitive form, identified mental states with actual behaviour: emotions with the muscular preliminaries of appropriate bodily movement, thoughts with subvocal motions in the larynx.
