This point is important when one considers the wider framework to which the interaction principle contributes. Since Davidson is attempting to derive monism from it and other principles that are themselves neutral about the metaphysics of mind, he cannot assume that action is (identical with) behavior on pain of circularity. Once monism has been established, Davidson will be in a position to deploy the ‘because’ point in order to argue for the claim that mental events are causally efficacious wi