Game theory suggests that evolution probably selected for two stable orientations toward human cooperation: tit for tat (often called "strong reciprocity") and permanent defection.91 Tit for tat is generally what we see throughout society: you show me some kindness, and I am eager to return the favor; you do something rude or injurious, and the temptation to respond in kind becomes difficult to resist. But consider how permanent defection would appear at the level of human relationships: the defector would probably engage in continuous cheating and manipulation, sham moralistic aggression (to provoke guilt and altruism in others), and strategic mimicry of positive social emotions like sympathy (as well as of negative emotions like guilt). This begins to sound like garden-variety psychopathy. The existence of psychopaths, while otherwise quite mysterious, would seem to be predicted by game theory. And yet, the psychopath who lives his entire life in a tiny village must be at a terrible disadvantage. The stability of permanent defection as a strategy would require that a defector be able to find people to fleece who are not yet aware of his terrible reputation. Needless to say, the growth of cities has made this way of life far more practicable than it has ever been.
Evil
When confronted with psychopathy at its most extreme, it is very difficult not to think in terms of good and evil. But what if we adopt a more naturalistic view? Consider the prospect of being locked in a cage with a wild grizzly: why would this be a problem? Well, clearly, wild grizzlies suffer some rather glaring cognitive and emotional deficits. Your new roommate will not be easy to reason with or placate; he is unlikely to recognize that you have interests analogous to his own, or that the two of you might have shared interests; and if he could understand such things, he would probably lack the emotional resources to care. From his point of view, you will be a distraction at best, a cowering annoyance, and something tender to probe with his teeth. We might say that a wild bear is, like a psychopath, morally insane. However, we are very unlikely to refer to his condition as a form of "evil."
Human evil is a natural phenomenon, and some level of predatory violence is innate in us. Humans and chimpanzees tend to display the same level of hostility toward outsiders, but chimps are far more aggressive than humans are within a group (by a factor of about 200). 92 Therefore, we seem to have prosocial abilities that chimps lack. And, despite appearances, human beings have grown steadily less violent. As Jared Diamond explains:
It's true, of course, that twentieth-century state societies, having developed potent technologies of mass killing, have broken all historical records for violent deaths. But this is because they enjoy the advantage of having by far the largest populations of potential victims in human history; the actual percentage of the population that died violently was on the average higher in traditional pre-state societies than it was even in Poland during the Second "World War or Cambodia under Pol Pot. 93
We must continually remind ourselves that there is a difference between what is natural and what is actually good for us. Cancer is perfectly natural, and yet its eradication is a primary goal of modern medicine. Evolution may have selected for territorial violence, rape, and other patently unethical behaviors as strategies to propagate one's genes—but our collective well-being clearly depends on our opposing such natural tendencies.
Territorial violence might have even been necessary for the development of altruism. The economist Samuel Bowles has argued that lethal, "out-group" hostility and "in-group" altruism are two sides of the same coin. 94 His computer models suggest that altruism cannot emerge without some level of conflict between groups. If true, this is one of the many places where we must transcend evolutionary pressures through reason—because, barring an attack from outer space, we now lack a proper "out-group" to inspire us to further altruism.
In fact, Bowles's work has interesting implications for my account of the moral landscape. Consider the following from Patricia Churchland:
Assuming our woodland ape ancestors as well as our own human ancestors engaged in out-group raids, as chimps and several South American tribes still do, can we be confident in moral condemnation of their behavior? I see no basis in reality for such a judgment. If, as Samuel Bowles argues, the altruism typical of modern humans plausibly co-evolved with lethal out-group competition, such a judgment will be problematic. 95
Of course, the purpose of my argument is to suggest a "basis in reality" for universal judgments of value. However, as Churchland points out, if there was simply no other way for our ancestors to progress toward altruism without developing a penchant for out-group hostility, then so be it. Assuming that the development of altruism represents an extraordinarily important advance in moral terms (I believe it does), this would be analogous to our ancestors descending into an unpleasant valley on the moral landscape only to make progress toward a higher peak. But it is important to reiterate that such evolutionary constraints no longer hold. In fact, given recent developments in biology, we are now poised to consciously engineer our further evolution. Should we do this, and if so, in which ways? Only a scientific understanding of the possibilities of human well-being could guide us.
The Illusion of Free Will
Brains allow organisms to alter their behavior and internal states in response to changes in the environment. The evolution of these structures, tending toward increased size and complexity, has led to vast differences in how the earth's species live.
The human brain responds to information coming from several domains: from the external world, from internal states of the body, and, increasingly, from a sphere of meaning—which includes spoken and written language, social cues, cultural norms, rituals of interaction, assumptions about the rationality of others, judgments of taste and style, etc. Generally, these domains seem unified in our experience: You spot your best friend standing on the street corner looking strangely disheveled. You recognize that she is crying and frantically dialing her cell phone. Did someone assault her? You rush to her side, feeling an acute desire to help. Your "self" seems to stand at the intersection of these lines of input and output. From this point of view, you tend to feel that you are the source of your own thoughts and actions. You decide what to do and not to do. You seem to be an agent acting of your own free will. As we will see, however, this point of view cannot be reconciled with what we know about the human brain.
We are conscious of only a tiny fraction of the information that our brains process in each moment. While we continually notice changes in our experience—in thought, mood, perception, behavior, etc.—we are utterly unaware of the neural events that produce these changes. In fact, by merely glancing at your face or listening to your tone of voice, others are often more aware of your internal states and motivations than you are. And yet most of us still feel that we are the authors of our own thoughts and actions.
All of our behavior can be traced to biological events about which we have no conscious knowledge: this has always suggested that free will is an illusion. For instance, the physiologist Benjamin Libet famously demonstrated that activity in the brain's motor regions can be detected some 350 milliseconds before a person feels that he has decided to move. 96 Another lab recently used fMRI data to show that some "conscious" decisions can be predicted up to 10 seconds before they enter awareness (long before the preparatory motor activity detected by Libet). 97 Clearly, findings of this kind are difficult to reconcile with the sense that one is the conscious source of one's actions. Notice that distinction between "higher" and "lower" systems in the brain gets us nowhere: for I no more initiate events in executive regions of my prefrontal cortex than I cause the creaturely outbursts of my limbic system. The truth seems inescapable: I, as the subject of my experience, cannot know what I will next think or do until a thought or intention arises; and thoughts and intentions are caused by physical events and mental stirrings of which I am not aware.
Many scientists and philosophers realized long ago that free will could not be squared with our growing understanding of the physical wo
rld. 98 Nevertheless, many still deny this fact. 99 The biologist Martin Heisenberg recently observed that some fundamental processes in the brain, like the opening and closing of ion channels and the release of synaptic vesicles, occur at random, and cannot, therefore, be determined by environmental stimuli. Thus, much of our behavior can be considered "self-generated," and therein, he imagines, lies a basis for free will. 100 But "self-generated" in this sense means only that these events originate in the brain. The same can be said for the brain states of a chicken.
If I were to learn that my decision to have a third cup of coffee this morning was due to a random release of neurotransmitters, how could the indeterminacy of the initiating event count as the free exercise of my will? Such indeterminacy, if it were generally effective throughout the brain, would obliterate any semblance of human agency. Imagine what your life would be like if all your actions, intentions, beliefs, and desires were "self-generated" in this way: you would scarcely seem to have a mind at all. You would live as one blown about by an internal wind. Actions, intentions, beliefs, and desires are the sorts of things that can exist only in a system that is significantly constrained by patterns of behavior and the laws of stimulus-response. In fact, the possibility of reasoning with other human beings—or, indeed, of finding their behaviors and utterances comprehensible at all—depends on the assumption that their thoughts and actions will obediently ride the rails of a shared reality. In the limit, Heisenberg's "self-generated" mental events would amount to utter madness. 101
The problem is that no account of causality leaves room for free will. Thoughts, moods, and desires of every sort simply spring into view— and move us, or fail to move us, for reasons that are, from a subjective point of view, perfectly inscrutable. Why did I use the term "inscrutable" in the previous sentence? I must confess that I do not know. Was I free to do otherwise? What could such a claim possibly mean? Why, after all, didn't the word "opaque" come to mind? Well, it just didn't— and now that it vies for a place on the page, I find that I am still partial to my original choice. Am I free with respect to this preference? Am I free to feel that "opaque" is the better word, when I just do not feel that it is the better word? Km I free to change my mind? Of course not. It can only change me.
It means nothing to say that a person would have done otherwise had he chosen to do otherwise, because a person's "choices" merely appear in his mental stream as though sprung from the void. In this sense, each of us is like a phenomenological glockenspiel played by an unseen hand. From the perspective of your conscious mind, you are no more responsible for the next thing you think (and therefore do) than you are for the fact that you were born into this world. 102
Our belief in free will arises from our moment-to-moment ignorance of specific prior causes. The phrase "free will" describes what it feels like to be identified with the content of each thought as it arises in consciousness. Trains of thought like, "What should I get my daughter for her birthday? I know, I'll take her to a pet store and have her pick out some tropical fish," convey the apparent reality of choices, freely made. But from a deeper perspective (speaking both subjectively and objectively), thoughts simply arise (what else could they do?) unauthored and yet author to our actions.
As Daniel Dennett has pointed out, many people confuse determinism with fatalism. 103 This gives rise to questions like, "If everything is determined, why should I do anything? Why not just sit back and see what happens?" But the fact that our choices depend on prior causes does not mean that they do not matter. If I had not decided to write this book, it wouldn't have written itself. My choice to write it was unquestionably the primary cause of its coming into being. Decisions, intentions, efforts, goals, willpower, etc., are causal states of the brain, leading to specific behaviors, and behaviors lead to outcomes in the world. Human choice, therefore, is as important as fanciers of free will believe. And to "just sit back and see what happens" is itself a choice that will produce its own consequences. It is also extremely difficult to do: just try staying in bed all day waiting for something to happen; you will find yourself assailed by the impulse to get up and do something, which will require increasingly heroic efforts to resist.
Of course, there is a distinction between voluntary and involuntary actions, but it does nothing to support the common idea of free will (nor does it depend upon it). The former are associated with felt intentions (desires, goals, expectations, etc.) while the latter are not. All of the conventional distinctions we like to make between degrees of intent—from the bizarre neurological complaint of alien hand syndrome 1 04 to the premeditated actions of a sniper—can be maintained: for they simply describe what else was arising in the mind at the time an action occurred. A voluntary action is accompanied by the felt intention to carry it out, while an involuntary action isn't. Where our intentions themselves come from, however, and what determines their character in every instant, remains perfectly mysterious in subjective terms. Our sense of free will arises from a failure to appreciate this fact: we do not know what we will intend to do until the intention itself arises. To see this is to realize that you are not the author of your thoughts and actions in the way that people generally suppose. This insight does not make social and political freedom any less important, however. The freedom to do what one intends, and not to do otherwise, is no less valuable than it ever was.
Moral Responsibility
The question of free will is no mere curio of philosophy seminars. The belief in free will underwrites both the religious notion of "sin" and our enduring commitment to retributive justice. 105 The Supreme Court has called free will a "universal and persistent" foundation for our system of law, distinct from "a deterministic view of human conduct that is inconsistent with the underlying precepts of our criminal justice system" (United States v. Grayson, 1978). 106 Any scientific developments that threatened our notion of free will would seem to put the ethics of punishing people for their bad behavior in question. 107
But, of course, human goodness and human evil are the product of natural events. The great worry is that any honest discussion of the underlying causes of human behavior seems to erode the notion of moral responsibility. If we view people as neuronal weather patterns, how can we coherently speak about morality? And if we remain committed to seeing people as people, some who can be reasoned with and some who cannot, it seems that we must find some notion of personal responsibility that fits the facts.
What does it really mean to take responsibility for an action? For instance, yesterday I went to the market; as it turns out, I was fully clothed, did not steal anything, and did not buy anchovies. To say that I was responsible for my behavior is simply to say that what I did was sufficiently in keeping with my thoughts, intentions, beliefs, and desires to be considered an extension of them. If, on the other hand, I had found myself standing in the market naked, intent upon stealing as many tins of anchovies as I could carry, this behavior would be totally out of character; I would feel that I was not in my right mind, or that I was otherwise not responsible for my actions. Judgments of responsibility, therefore, depend upon the overall complexion of one's mind, not on the metaphysics of mental cause and effect.
Consider the following examples of human violence:
1. A four-year-old boy was playing with his father's gun and killed a young woman. The gun had been kept loaded and unsecured in a dresser drawer.
2. A twelve-year-old boy, who had been the victim of continuous physical and emotional abuse, took his father's gun and intentionally shot and killed a young woman because she was teasing him.
3. A twenty-five-year-old man, who had been the victim of continuous abuse as a child, intentionally shot and killed his girlfriend because she left him for another man.
4. A twenty-five-year-old man, who had been raised by wonderful parents and never abused, intentionally shot and killed a young woman he had never met "just for the fun of it."
5. A twenty-five-year-old man, who had been raised by wonderful parents a
nd never abused, intentionally shot and killed a young woman he had never met "just for the fun of it." An MPT of the man's brain revealed a tumor the size of a golf ball in his medial prefrontal cortex (a region responsible for the control of emotion and behavioral impulses).
In each case a young woman has died, and in each case her death was the result of events arising in the brain of another human being. The degree of moral outrage we feel clearly depends on the background conditions described in each case. We suspect that a four-year-old child cannot truly intend to kill someone and that the intentions of a twelve-year-old do not run as deep as those of an adult. In both cases 1 and 2, we know that the brain of the killer has not fully matured and that all the responsibilities of personhood have not yet been conferred. The history of abuse and precipitating circumstance in example 3 seem to mitigate the man's guilt: this was a crime of passion committed by a person who had himself suffered at the hands of others. In 4, we have no abuse, and the motive brands the perpetrator a psychopath. In 5, we appear to have the same psychopathic behavior and motive, but a brain tumor somehow changes the moral calculus entirely: given its location in the MPFC, it seems to divest the killer of all responsibility. How can we make sense of these gradations of moral blame when brains and their background influences are, in every case, and to exactly the same degree, the real cause of a woman's death?