“Well, moving swiftly sideways into cognitive neuroscience…In the past twenty years we’ve made huge strides, using imaging tools, direct brain interfaces, and software simulations. We’ve pretty much disproved the existence of free will, at least as philosophers thought they understood it. A lot of our decision-making mechanics are subconscious; we only become aware of our choices once we’ve begun to act on them. And a whole lot of other things that were once thought to correlate with free will turn out also to be mechanical. If we use transcranial magnetic stimulation to disrupt the right temporoparietal junction, we can suppress subjects’ ability to make moral judgements; we can induce mystical religious experiences: We can suppress voluntary movements, and the patients will report that they didn’t move because they didn’t want to move. The TMPJ finding is deeply significant in the philosophy of law, by the way: It strongly supports the theory that we are not actually free moral agents who make decisions—such as whether or not to break the law—of our own free will.
“In a nutshell, then, what I’m getting at is that the project of law, ever since the Code of Hammurabi—the entire idea that we can maintain social order by obtaining voluntary adherence to a code of permissible behaviour, under threat of retribution—is fundamentally misguided.” His eyes are alight; you can see him in the Cartesian lecture-theatre of your mind, pacing door-to-door as he addresses his audience. “If people don’t have free will or criminal intent in any meaningful sense, then how can they be held responsible for their actions? And if the requirements of managing a complex society mean the number of laws have exploded until nobody can keep track of them without an expert system, how can people be expected to comply with them?”

Source: Rule 34 (2011), Chapter 26, “Liz: It’s Complicated” (pp. 286-287)