The sciences of the mind do give us good reasons to think that our minds are made of matter. But to conclude that consciousness or free will is thereby an illusion is too quick. It is like inferring from discoveries in organic chemistry that life is an illusion just because living organisms are made up of non-living stuff. Much of the progress in science comes precisely from understanding wholes in terms of their parts, without this suggesting the disappearance of the wholes. There’s no reason to define the mind or free will in a way that begins by cutting off this possibility for progress.but,
...people sometimes misunderstand determinism to mean that we are somehow cut out of the causal chain leading to our actions. People are threatened by a possibility I call “bypassing” — the idea that our actions are caused in ways that bypass our conscious deliberations and decisions. So, if people mistakenly take causal determinism to mean that everything that happens is inevitable no matter what you think or try to do, then they conclude that we have no free will.
...discoveries about how our brains work can also explain how free will works rather than explaining it away. But first, we need to define free will in a more reasonable and useful way. Many philosophers, including me, understand free will as a set of capacities for imagining future courses of action, deliberating about one’s reasons for choosing them, planning one’s actions in light of this deliberation and controlling actions in the face of competing desires. We act of our own free will to the extent that we have the opportunity to exercise these capacities, without unreasonable external or internal pressure. We are responsible for our actions roughly to the extent that we possess these capacities and we have opportunities to exercise them.In response to numerous comments on his article Nahmias notes:
...As long as people understand that discoveries about how our brains work do not mean that what we think or try to do makes no difference to what happens, then their belief in free will is preserved. What matters to people is that we have the capacities for conscious deliberation and self-control that I’ve suggested we identify with free will.
...None of the evidence marshaled by neuroscientists and psychologists suggests that those neural processes involved in the conscious aspects of such complex, temporally extended decision-making are in fact causal dead ends. It would be almost unbelievable if such evidence turned up. It would mean that whatever processes in the brain are involved in conscious deliberation and self-control — and the substantial energy these processes use — were as useless as our appendix, that they evolved only to observe what we do after the fact, rather than to improve our decision-making and behavior. No doubt these conscious brain processes move too slowly to be involved in each finger flex as I type, but as long as they play their part in what I do down the road — such as considering what ideas to type up — then my conscious self is not a dead end, and it is a mistake to say my free will is bypassed by what my brain does.
So, does neuroscience mean the death of free will? Well, it could if it somehow demonstrated that conscious deliberation and rational self-control did not really exist or that they worked in a sheltered corner of the brain that has no influence on our actions. But neither of these possibilities is likely. True, the mind sciences will continue to show that consciousness does not work in just the ways we thought, and they already suggest significant limitations on the extent of our rationality, self-knowledge, and self-control. Such discoveries suggest that most of us possess less free will than we tend to think, and they may inform debates about our degrees of responsibility. But they do not show that free will is an illusion.
If we put aside the misleading idea that free will depends on supernatural souls rather than our quite miraculous brains, and if we put aside the mistaken idea that our conscious thinking matters most in the milliseconds before movement, then neuroscience does not kill free will. Rather, it can help to explain our capacities to control our actions in such a way that we are responsible for them. It can help us rediscover free will.
One point I did not have time to develop, but many comments raise, is that we do not possess as much free will as we tend to think...Psychology indeed suggests that we are often unaware of what motivates us, we often rationalize our actions after we act, and we often are influenced by external factors that we'd prefer not to be influenced by... because I understand free will as a set of naturalistic capacities, I believe that empirical discoveries can illuminate not only how it works, but also limitations to it. This also means we are sometimes less praiseworthy or blameworthy than we tend to think...Conversely, I do not think that free and responsible action always requires conscious or rational deliberation. As Aristotle taught us, we are responsible not only for these sorts of choices but also for our habits and character traits that derive from these choices, though again, it largely remains to be discovered what degrees of freedom and responsibility we possess.