Why Causation is Biconditional but not Proportional

In this article, I defend a biconditional counterfactual account of causation, which places equal emphasis on what I call “the presence condition” and “the absence condition,” whereas Lewis's classical counterfactual theory focuses only on the absence condition. I attempt to show that biconditionalism provides a promising treatment of supervenient causation, namely, causal cases involving the supervenience relationship. Although some philosophers confuse this account with the proportionality constraint on causation, I argue that biconditionalism is distinct from and superior to proportionalism in accommodating our reliable causal intuitions.