Why Libet-Style Experiments Cannot Refute All Forms of Libertarianism

Abstract

Since Benjamin Libet published the results of his well-known experiments (Libet 1985; Libet–Gleason–Wright–Pearl 1983), it has been heavily debated whether these results refute the existence of free will. Most philosophers who are experts on the topic of free will have reached the conclusion that Libet’s original experiments and other Libet-style experiments have not provided enough evidence for denying free will yet.1 However, the problem as to whether Libet-style experiments could in principle refute free will has not been discussed as much and it seems that there is no consensus on this matter. Recently, Marcelo Fischborn (2016, 2017) has attempted to shed light on why Libet-style experiments can in principle refute libertarian theories of free will. According to Fischborn, Libet-style experiments can in principle refute libertarian free will because (i) libertarian free will is incompatible with a local determinism in the brain that would make choice predetermined by unconscious brain states and (ii) Libet-style experiments are in principle able to support that there is such a local determinism in the brain. Against Fischborn, Adina Roskies and Eddy Nahmias (2017) have argued in accordance with their earlier papers (Roskies 2006, Nahmias 2014) that Fischborn is wrong because it is not true either that libertarian free will is incompatible with local determinism or that Libet-style experiments are able to support local or universal determinism. Although I think that this debate merits attention, both sides share a false presupposition, namely, that the different libertarian theories are similar to each other with regard to what they claim about the role and location of indeterminism in free decisions. Fischborn seems to think that libertarians agree