The problem of free will is deeply linked with the causal relevance of mental events. The causal exclusion argument claims that, in order to be causally relevant, mental events must be identical to physical events. However, Gibb has recently criticized it, suggesting that mental events are causally relevant as double preventers. For Gibb, mental events enable physical effects to take place by preventing other mental events from preventing a behaviour to take place. The role of mental double preventers is hence similar to what Libet names free won’t, namely the ability to veto an action initiated unconsciously by the brain. In this paper I will propose an argument against Gibb’s account, the causal irrelevance argument, showing that Gibb’s p...