Before the story can be told, however, some stage-setting is necessary. First, it is important to be clear about the most basic doctrines of Pre-established Harmony, Occasionalism, and Physical Influx. Physical Influx asserts intersubstantial causation amongst finite substances. For instance, when I appear to kick a ball, I really am the cause of the ball's motion. Pre-established Harmony denies intersubstantial causation, but affirms intrasubstantial causation. According to Pre-established Harmony, then, I am not the cause of the ball's motion, but rather (...) the ball is simply causing itself to move. Occasionalism, like Pre-established Harmony, denies intersubstantial causation, but, unlike Pre-established Harmony, it denies intrasubstantial causation as well. Occasionalism typically asserts that God alone, that is, an infinite substance, is the cause of all changes, and thus of the ball's motion. Though there are other ways of defining these causal theories, this way has the advantage that the causal theories form an exhaustive disjunction. (shrink)