ABSTRACT
One of the marks, though not a necessary mark, of a really great philosopher is to make a really great mistake: that is to say, to give a persuasive and lastingly influential form to one of those fundamental misconceptions to which the human intellect is prone when it concerns itself with the ultimate categories of thought. So today, more than three hundred years after the death of René Descartes, philosophers struggling with one of these fundamental misconceptions think of it under the name of Cartesian dualism. Not that they all think of the doctrine in question as a misconception. The doctrine has its defenders. Indeed if it did not represent a way of thinking about mind and body which has a powerful intellectual appeal, it would not be worth struggling against. There is little point in refuting errors which no one is inclined to make.
