ABSTRACT
P: In my sections 48 —56 I have given a history of the body-mind problem since Descartes and especially of the steps which led to parallelism-the parallelism of Geulincx, of Malebranche, of Spinoza, and of Leibniz. I have tried to show that the emergence of parallelism is almost completely based on the view that we have a valid theory of causation in World 1 - that bodies behave just as if pushing each other and so causing one another to move (which is the Cartesian theory of causation). There was also a theory of causation in World 2, namely that one idea is associated with another and therefore that the recalling of one idea, a, brings about as a sequel the appearance in the consciousness of the idea, b. So there are two simple theories o f causation, one for World 1 and one for World 2; and given these theories it appears to be completely ununderstandable that World 1 and World 2 can interact. This apparent impossibility of interaction leads to the parallelism of Geulincx, Malebranche, Spinoza and Leibniz.
