The argument from causal overdetermination is considered to be the shortest route to token monism. It only assumes that:1.Efficacy: Mental events are causes of physical events.2.Closure: Every physical event has a sufficient physical cause.3.Exclusion: Systematic Causal Overdetermination is impossible: if an event x is a sufficient cause of an event y then no event x* distinct from x is a cause of y.4.Identity: Therefore, mental events are physical events.Exclusion does not deny the possibility of two gunmen that fi re at (...) a victim at the same time. But event-dualism is like a systematic fi ringsquad case — whenever I want to raise my arm, my arm is raised, and that is intolerable. (shrink)