The Principle of the Causal Openness of the Physical

The argument from causal closure for physicalism requires the principle that a physical event can only occur through being necessitated by antecedent physical events. This article proposes a view of the causal structure of the world that claims not only that an event need not be necessitated by antecedent events, but that an event cannot be necessitated by antecedent events. All events are open to counteraction. In order to spell out various kinds of counteraction I introduce the idea of ‘directedness.’