Eddy Nahmias in Big Questions Online:
Humans love stories. We tell each other the stories of our lives, in which we are not merely players reading a script but also the authors. As authors we make choices that influence the plot and the other players on the stage. Free will can be understood as our capacities both to make choices—to write our own stories—and to carry them out on the world’s stage—to control our actions in light of our choices.
What would it mean to lack free will? It might mean we are merely puppets, our strings pulled by forces beyond our awareness and beyond our control. It might mean we are players who merely act out a script we do not author. Or perhaps we think we make up our stories, but in fact we do so only after we’ve already acted them out. The central image in each case is that we merely observe what happens, rather than making a difference to what happens.
How might neuroscience fit into the story I am telling? Most scientists who discuss free will say the story has an unhappy ending—that neuroscience shows free will to be an illusion. I call these scientists “willusionists.” (Willusionists include Sam Harris, Jerry Coyne, Jonathan Bargh, Daniel Wegner, John Dylan Haynes, and as suggested briefly in some of their work, Stephen Hawking and Richard Dawkins.) Willusionists say that neuroscience demonstrates that we are not the authors of our own stories but more like puppets whose actions are determined by brain events beyond our control. In his new book Free Will, Sam Harris says, “This [neuroscientific] understanding reveals you to be a biochemical puppet.” Jerry Coyne asserts in a USAToday column: “The ineluctable scientific conclusion is that although we feel that we’re characters in the play of our lives, rewriting our parts as we go along, in reality we’re puppets performing scripted parts written by the laws of physics.”
There are several ways willusionists reach their conclusion that we lack free will. The first begins by defining free will in a dubious way. Most willusionists’ assume that, by definition, free will requires a supernatural power of non-physical minds or souls: it’s only possible if we are somehow offstage, beyond the causal interactions of the natural world, yet also somehow able to pull the strings of our bodies nonetheless.(For example, Read Montague.) It’s a mysterious picture, and one that willusionists simply assert is the ordinary understanding of free will. Based on this definition of free will, they then conclude that neuroscience challenges free will, since it replaces a non-physical mind or soul with a physical brain.
But there is no reason to define free will as requiring this dualist picture.