Counterfactuals, Overdetermination and Mental Causation

The Exclusion Problem for mental causation suggests that there is a tension between the claim that the mental causes physical effects, and the claim that the mental does not overdetermine its physical effects. In response, Karen Bennett puts forward an extra necessary condition for overdetermination : if one candidate cause were to occur but the other were not to occur, the effect would still occur. She thus denies one of the assumptions of EP, the assumption that if an effect has two sufficient causes, it is overdetermined. If sound, her argument does two things: it solves EP, and it shows how to use counterfactuals in order to make the notion of overdetermination precise. However, the argument is not sound