Another Scientific Threat to Free Will

The claim that neuroscientists have proved that - or at least produced powerful evidence that - free will is an illusion has received a lot of press. Here are just two examples:"Free will" is not the defining feature of humanness, modern neuroscience implies, but is rather an illusion that endures only because biochemical complexity conceals the mechanisms of decision making. (Science News, Dec. 6, 2008; Siegfried [2008])Researchers have found patterns of brain activity that predict people's decisions up to 10 seconds before they're aware they've made a choice. . . . The result was hard for some to stomach because it suggested that the unconscious brain calls the shots, making free will an illusory afterthought. (ScienceNOW Daily News, April 14, 2008; Youngsteadt [2008])In Effective Intentions: The Power of Conscious Will (Mele 2009), I argue that scientists - neuroscientists and others - have not proved that free will is an illusion and have not produced powerful evidence for that claim. Manuel Vargas has suggested that in that book I ignore a serious scientific threat to free will (2009). The alleged threat is identified in section 1 . It is me topic of this article.Scientists who argue for the illusion thesis about free will arrive at that conclusion by way of some pretty striking empirical propositions that they infer from their data. For example, Benjamin Libet contends that the brain produces unconscious decisions to act about a third of a second before the person becomes aware of them (1985, 2004), and Daniel Wegner argues that "conscious intentions" are never among the causes of corresponding actions (2002, 2004, 2008). In Effective Intentions I review me experiments that are claimed to support striking empirical propositions such as these and I explain why the propositions are not justified by the data. Because these empirical propositions play a central role in the reasoning that leads such scientists as Libet and Wegner to their conclusions about free will, if my arguments that the propositions are not justified by the data hit their mark, they undermine the scientific arguments at issue about free will. For example, it may be plausible that a person whose conscious intentions never play a role in producing corresponding behavior never acts freely; but if we lack good reason to believe that our conscious intentions never play a role of this kind, this particular line of argument for the thesis that free will is an illusion is out of the running (at least until powerful evidence for the claim about conscious intentions is produced).1. What Threatens Free Will?In a review ?? Effective Intentions, Manuel Vargas suggests that "the core threat" to free will might arise not from the striking empirical propositions that I discuss there, but instead "from the bare fact that there are neurological antecedents to conscious decisions. . . . What is really at stake is whether our conscious intentions, even given some role in the production of action, can be picked out of the causal nexus and treated as special or 'free'" (2009). He offers the following diagnosis of what scientists I disagree with might be thinking:[They] are sometimes motivated by what the philosophical literature labels as "source" intuitions - the idea that for us to act with a free will we must be the ultimate origins of strands of the causal nexus. On one way of putting things, source theorists think that free acts cannot have causal antecedents that extend back in time prior to the decisions of the agent or the agent's free formulation of the relevant characterological inputs to that decision. . . . Acknowledging that our actions have causal roots in pre-conscious brain activity, as Mele does, just highlights the fact of our causal embeddedness. It does nothing to block the basic worry of how we could be the kinds of beings that stop the buck enough to count as free, or as deserving of moral praise and blame. …