I finally had a chance to read Sam Harris’s book on Free Will and to my surprise I agreed with most of it. This opening paragraph summarizes his view:


“If the scientific community were to declare free will an illusion, it would precipitate a culture war far more belligerent than the one that has been waged on the subject of evolution. Without free will, sinners and criminals would be nothing more than poorly calibrated clockwork, and any conception of justice that emphasized punishing them (rather than deterring, rehabilitating, or merely containing them) would appear utterly incongruous. And those of us who work hard and follow the rules would not “deserve” our success in any deep sense.“


I agree with everything he says there. He spends a good deal of the book talking about how there is no such thing as sin and that criminals should be punished for the sake of deterrence and rehabilitation not for revenge or some abstract notion of justice. I agree with all of that.


The one area where I disagree with Harris is on his theory of mind. He seems to believe that the eventual theory of psychology that will emerge will be something like behaviorism, a theory where human intentions aren’t objects of study. Harris claims that any scientific theory of psychology must prove two things to be false:


“1) that each of us could have behaved differently than we did in the past, and 2) that we are the conscious source of most of our thoughts and actions in the present” (p. 6)


Refuting the first point is simply a necessary conclusion of the fact that humans are part of the natural universe. Refuting the second point however, makes an assumption about the future of psychology that is far from a given. Harris assumes that human internal cognitive states have no significant causative role in human behavior.


One of his main arguments, which is implicit in the book, he never justifies it he simply assumes it to be true, is that human cognition must be 100% responsible for every possible aspect of behavior or it must play no role at all. The possibility that goals and plans may be partially responsible for human behavior (along with environment, learning, genetics, etc.) doesn’t seem to be a viable option for him.


For example, when describing how his theory of free will works even with a soul concept he says: “The unconscious operations of a soul would grant you no more freedom than the unconscious physiology of your brain does. If you don’t know what your soul is going to do next you are not in control” (p. 12) and then later he says: “Consider what it would take to actually have free will. You would need to be aware of all the factors that determine your thoughts and actions, and you would need to have complete control over those factors” (p. 13)


In several other sections he talks about various physical and experiential causes that can negate free will and always draws the conclusion that lack of total free will means no free will at all. This is a very simplistic theory of psychology. No theory that I’m aware of from Freud onward, claims that humans are the one and only source of their intentions. Indeed Freud’s biggest (some might claim only significant) accomplishment was to demonstrate that human actions can be caused by beliefs and intentions that the individual is not completely aware or in control of. It is a huge unsubstantiated leap however to jump from that to saying that therefor human intentions play no role whatever in human behavior.


Harris doesn’t go into much detail about his ideas on psychology but to the extent that he does he focuses on neurophysiological explanations. His psychology seems to be a very reductionist version of neurophysiology:  “It is one thing to bicker with your wife because you are in a bad mood, its another to realize that your mood and behavior have been caused by low blood sugar. This understanding reveals you to be a biochemical puppet of course” (p. 47)


Harris’s psychology relegates conscious thoughts and intentions to incidental epiphenomena. That is one possible view of psychology that would be supported for example by B. F. Skinner. Neurophysiology is of course essential to psychology but there are potential paradigms where human behavior isn’t explained simply by reducing it to neurophysiology. For example, the modular model described by Steven Pinker in How the Mind Works:  


“the mind is a complex system of neural information processing that builds mental models of the physical and social world and pursues goals which are ultimately related to survival and reproduction in a pre-modern environment.”


The goals that Pinker refers to are human intentions, the things that Harris dismisses as irrelevant to the cause of human behavior. For Pinker and many other cognitive scientists such as Dan Dennett and Scott Atran these intentions are worthy of study and almost certainly play some causal role in human behavior. Unlike Harris, I think this is still an open question. I don’t think any theory of mind we currently have is mature enough for anyone to say with certainty in what manner and to what degree human intentions cause human behavior. However, I think it is a totally unjustified leap to assume them away and in fact doing so would be a barrier to some very interesting cognitive science research currently in progress.