Sapolsky (6): Determinism, Free Will, and Natural Freedom in the Legal System

In 1987, Robert Sapolsky was the recipient of one of the MacArthur Foundation's "genius grants."  Some years later, he received a letter from the Foundation asking him to submit some Big Ideas for a funding initiative.  The letter said something like "Send us a provocative idea, something you'd never propose to another foundation because they'd label you crazy." 

So he sent them a proposal titled "Should the Criminal Justice System Be Abolished?"  He argued that the answer was clearly yes, because neuroscience had proven that all human conduct is biologically determined, and therefore there is no free will, which means that the criminal justice system is wrong in holding people morally responsible for their behavior.  When the Foundation accepted this proposal and organized a conference on this, Sapolsky and other neuroscientists began debating lawyers, law professors, and judges, who tried to defend the standards of legal responsibility against Sapolsky's claim that those standards are unscientific in so far as they assume free will.  As a result of this conference, the Foundation has funded a general program for "neurolaw"--applying neuroscience to the study of law--and one of the primary issues has continued to be this debate over whether neuroscience justifies abolishing a legal system that assumes the reality of free will.

Ah yes, many of my critics would say, don't you see here, Arnhart, that this is the disastrous consequence of your biological science of human nature--biological determinism denies the concept of free will that supports our legal and moral judgments of human responsibility?  The only way to avoid this, they insist, is to recognize that human beings have a spiritual capacity for free will that transcends their biological nature and for which there is no natural biological explanation.

In response to this criticism, I have argued that biological explanations of human nature in general and of the human brain in particular are fully compatible with traditional conceptions of moral and legal responsibility (see my posts here, here, here, here, here, and here). 

To see this compatibility, we must reject the idea of "free will" as uncaused cause. Whatever comes into existence must have a cause. Only what is self-existent from eternity--God--could be uncaused or self-determined. The commonsense notion of liberty is power to act as one chooses regardless of the cause of the choice. Human freedom of choice is not freedom from nature but a natural freedom to deliberate about our natural desires so that we can organize and manage our desires through habituation and reflection to conform to some conception of a whole life well lived. This is how Aristotle understood "deliberate choice" (proairesis)

Similarly, Darwin believed that "every action whatever is the effect of a motive," and therefore he doubted the existence of "free will." Our motives arise from a complex interaction of innate temperament, individual experience, social learning, and external conditions. Still, although we are not absolutely free of the causal regularities of nature, Darwin believed, we are morally responsible for our actions because of our uniquely human capacity for reflecting on our motives and circumstances and acting in the light of those reflections. "A moral being is one who is capable of reflecting on his past actions and their motives--of approving of some and disapproving of others; and the fact that man is the one being who certainly deserves this designation is the greatest of all distinctions between him and the lower animals."

If we understand moral responsibility in this way, and see this as the conception of responsibility assumed in the law, then neuroscientific research on the natural causality of the brain is no threat to moral and legal responsibility. Stephen Morse--a law professor at the University of Pennsylvania Law School who specializes in psychology and law--has laid out the case for this conclusion based on a "compatibilist" view of moral choice.

As Morse indicates, the "hard determinists" and the "metaphysical libertarians" agree that "free will" would require a "contra-causal freedom." But while the determinists deny there is such a thing. The libertarians affirm its existence as an uncaused cause beyond natural causality. If we had to choose between these two positions, neuroscience would favor the determinists.

But Morse rightly argues that the law's conception of responsibility does not require a "contra-causal freedom." It requires only that human beings have sufficient practical rationality to understand their choices and to act on their deliberate decisions. When rationality is so diminished that someone cannot understand or act on his choices--a child or someone who is insane, for example--then we excuse their behavior and do not hold them fully responsible for their actions. But this conception of moral and legal responsibility as based on the capacity for practical deliberation or rationality does not require any transcendence of natural causality.

Sapolsky has debated Morse, and in Behave, he explains why he thinks Morse fails in his account of "mitigated free will" as compatible with the science of human behavioral biology.  I am now wondering whether the compatibilism that Morse and I share can be defended against Sapolsky's critique.

Sapolsky observes that there are three ways of viewing the influence of human biology on human behavior.  (1) We have complete free will in our behavior, because our behavior is always freely chosen, and it is never biologically caused.  (2) We have no free will, because our behavior is never freely chosen, and it is always biologically caused.  (3) Our behavior is somewhere in between these two extremes.

Almost no one takes the first position, because almost all of us recognize that sometimes people are compelled by biological causes to behave in ways that we have not freely chosen.  So, for example, in 1842, Daniel M'Naghten tried to assassinate British prime minister Robert Peel, and instead he killed Peel's private secretary, Edward Drummond.  He had been convinced that the Tories were persecuting him and even trying to murder him.  For years, he had heard voices telling him that Peel was spying on him.  He felt compelled to kill Peel.  At the trial, a doctor testified that he was insane.  Today, we would say he suffered from some form of paranoid psychosis.  He was declared innocent by reason of insanity, and for the rest of his life he was in insane asylums.  His case became the basis of the "M'Naghten rule" that someone can be innocent by reason of insanity if, at the time of the crime, the person is so "laboring under such a defect of reason from disease of the mind," that he cannot distinguish right from wrong.

In Anglo-American law, this shows the limits of free will when a diseased mind creates a compulsion that drives someone to commit a crime for which they are not fully responsible.

But as our scientific knowledge of the natural causes of behavior grows, Sapolsky observes, we can see that not just brain diseases like this but all human behaviors have natural biological causes.  And if all of our behavior is naturally caused, then we don't have free will, because we cannot act outside of the naturally causal world known to natural science.  So Sapolsky takes the second position--that there is no free will at all.

But Sapolsky admits that most human beings--or at least most of those who have thought deeply about this problem of free will--take the third position--that there is some middle ground between complete free will and no free will.  This is the position that the determinism of natural causes can be compatible with a limited free will. 

Those like Morse (and me) who defend compatibilism claim that human beings can have a natural freedom of choice that is not a free will understood as uncaused cause, and therefore this natural freedom is compatible with the determinism of natural cause.  Sapolsky denies this is possible, because he believes that any notion of human freedom must tacitly assume some kind of spiritual or immaterial power acting as uncaused cause.

Morse distinguishes between causation and compulsion.  The fact that all of our behavior is caused does not mean that all of it is compelled.  When we freely choose to think or act, what we do has been caused by our beliefs and desires, but this causation is not compulsion, and so we can be held legally or morally responsible for this.

Sapolsky responds: "But try as I might, I cannot see any way of making this distinction that does not tacitly require a homunculus that is outside the causal universe, a homunculus that can be overwhelmed by 'compulsion' but that can and should handle 'causation'" (600).

Although the compatibilists deny that they are metaphysical dualists, in fact, they really are, at least implicitly:

"There's the brain--neurons, synapses, neurotransmitters, receptors, brain-specific transcription factors, epigenetic effects, gene transpositions during neurogenesis.  Aspects of brain function can be influenced by someone's prenatal environment, genes, and hormones, whether their parents were authoritative or their culture egalitarian, whether they witnessed violence in childhood, when they had breakfast.  It's the whole shebang, all of this book."

"And then, separate from that, in a concrete bunker tucked away in the brain, sits a little man (or woman, or agendered individual), a homunculus at a control panel.  The homunculus is made of a mixture of nanochips, old vacuum tubes, crinkly ancient parchment, stalactites of your mother's admonishing voice, streaks of brimstone, rivets made out of gumption.  In other words, not squishy biological brain yuck."

"And the homunculus sits there controlling behavior.  There are some things outside its purview--seizures blow the homunculus's fuses, requiring it to reboot the system and check for damaged files.  Same with alcohol, Alzheimer's disease, a severed spinal cord, hypoglycemic shock."

"There are domains where the homunculus and that brain biology stuff have worked out a détente--for example, biology is usually automatically regulating your respiration, unless you must take a deep breath before singing an aria, in which case the homunculus briefly overrides the automatic pilot."

"But other than that, the homunculus makes decisions.  Sure, it takes careful note of all the inputs and information from the brain, checks your hormone levels, skims the neurobiology journals, takes it all under advisement, and then, after reflecting and deliberating, decides what you do.  A homunculus in your brain, but not of it, operating independently of the material rules of the universe that constitute modern science" (588).

In reply to this reductio ad absurdum argument, Morse and I will say that this is a straw man--or straw homunculus--argument, because we are not claiming that freedom of choice acts outside the causal laws of nature. But Sapolsky's claim is that despite what we say, we must implicitly or tacitly invoke such a homunculus acting outside the natural world.

Now, it should be noted that in defending a biological determinism that denies free will, Sapolsky is not a reductionist; nor is he claiming that biological science can predict behavior.  His biology of human behavior is a non-reductive multifactorial biology that sees behavior arising from a great multitude of factors interacting with one another, so that no single factor or set of factors acts as the single cause of the behavior.  So, for instance, genes influence behavior, but they do not by themselves determine behavior, because genes by themselves do nothing, and their influence depends on the various contexts in which they work.

Moreover, since this multifactorial biology is so complex, and since our scientific knowledge of how it works is so limited, we cannot now--and perhaps cannot ever--predict any behavior exactly.  We can only talk about what tends to happen on average in certain circumstances.  The variability of individuals and the variability of the contexts in which they act make precise prediction impossible.  We can say that people with paranoid psychosis will have some tendency to act as M'Naghten did, but he cannot say that every person with such a disease will do so.

So, if we were persuaded by Sapolsky that there is no free will or freedom of choice to support the standards of legal responsibility assumed by the criminal justice system today, then how would we have to reform the system to conform to this science of non-reductive multifactorial biological determinism?

Sapolsky says we should draw three conclusions--one is easy to see, one is hard to implement, and the third is almost impossible to achieve.

First, it should be easy to see that a legal system that denies free will would not have to allow dangerous people to roam freely in society and create havoc.  Of course, we need to protect ourselves from dangerous people, even though those dangerous people are acting under the disordered compulsions of their brains.  Here Sapolsky's neuroscience would not make any difference for the criminal justice system: we would continue to separate criminals from the rest of society for the protection of society.

But, then, the second conclusion is a little harder to adopt:  if we deny free will, then we can punish dangerous people by removing them from society, but we cannot see this punishment as justly deserved, as virtuous retribution for their immoral behavior.  It should not feel good to punish.  We cannot rightly feel that those we punish have earned their punishment.

The third conclusion, Sapolsky admits, is perhaps impossible to put into practice.  If we deny free will, then we cannot blame people for their bad behavior.  But it also follows that we cannot praise them for their good behavior, nor can we feel proud of ourselves for our good behavior.  For, if there is no free will, then no one deserves to be either praised or blamed.

It will be almost impossible for human beings to accept this.  So Sapolsky concedes:

"I can't really imagine how to live your life as if there is no free will.  It may never be possible to view ourselves as the sum of our biology.  Perhaps we'll have to settle for making sure our homuncular myths are benign, and save the heavy lifting of truly thinking rationally for where it matters--when we judge others harshly" (613).

"Our homuncular myths are benign," it seems, when we praise others for their accomplishments, but not when we judge others harshly.

It is not clear to me that Sapolsky can consistently deny human freedom of choice.  After all, his whole book Behave is an effort to persuade people to freely change the way they think and act--to see how the science of human behavioral biology can help them choose to create a world that is less violent, more peaceful, less vicious, and more virtuous than it is now.  He must conclude "that there is hope, that things can change, that we can be changed, that we personally can cause change" (648).

"That we can personally cause change"?  Well, yes, if we believe that we have the natural freedom to cause change.  But not if we believe that we have no such freedom.

Presumably, Sapolsky has written his book to try to persuade his readers with his arguments, and if he succeeds, this will change the neural circuitry in their frontal cortex and other parts of their brains in ways that can then exert some causal influence towards changing their behavior.  He is not trying to persuade a homunculus who can act as an uncaused cause.  Rather, he is trying to persuade those brain mechanisms that have the natural causal power to change behavior.  That is not free will.  That is the natural human freedom of choice.