Finally, let’s consider the suggestion that reason is incapable of contending against the brawn of the emotions, a tail that tries to wag the dog. The psychologists David Pizarro and Paul Bloom have argued that this is an over-interpretation of the laboratory phenomena of moral dumbfounding and other visceral reactions to moral dilemmas.214 Even if a decision is guided by intuition, the intuition itself may be a legacy of moral reasoning that had taken place beforehand, whether in private reflection, in dinner table debates, or through the assimilation of norms that were the output of past debates. Case studies reveal that at critical moments in an individual’s life (such as a woman’s decision to have an abortion), or at critical moments in a society’s history (such as the struggles over civil, women’s, and gay rights and the nation’s participation in war), people can be consumed in agonizing reflection and deliberation. We have seen many historic moral changes that originated in painstaking intellectual briefs, which were in turn met with furious rebuttals. Once the debate had been settled, the winning side entrenched itself in people’s sensibilities and erased its own tracks. Today, for example, people might be dumbfounded when asked whether we should burn heretics, keep slaves, whip children, or break criminals on the wheel, yet those very debates took place several centuries ago. We even saw a neuroanatomical basis for the give-andtake between intuition and reasoning in Joshua Greene’s studies of trolley problems in the brain scanner: each of these moral faculties has distinct neurobiological hubs.215
When Hume famously wrote that “reason is, and ought to be, only the slave of the passions,” he was not advising people to shoot from the hip, blow their stack, or fall head over heels for Mr. Wrong.216 He was basically making the logical point that reason, by itself, is just a means of getting from one true proposition to the next and does not care about the value of those propositions. Nonetheless there are many reasons why reason, working in conjunction with “some particle of the dove, kneaded into our frame,” must “direct the determinations of our mind, and where every thing else is equal, produce a cool preference of what is useful and serviceable to mankind, above what is pernicious and dangerous.” Let’s consider some of the ways the application of reason might be expected to reduce the rate of violence.
The chronological sequence in which the Scientific Revolution and the Age of Reason preceded the Humanitarian Revolution reminds us of one big reason, the one captured in Voltaire’s quip that absurdities lead to atrocities. A debunking of hogwash—such as the ideas that gods demand sacrifices, witches cast spells, heretics go to hell, Jews poison wells, animals are insensate, children are possessed, Africans are brutish, and kings rule by divine right—is bound to undermine many rationales for violence.
A second pacifying effect of exercising the faculty of reason is that it goes hand in hand with self-control. Recall that the two traits are statistically correlated in individuals and that their physiological substrates overlap in the brain.217 It is reason—a deduction of the long-term consequences of an action—that gives the self reasons to control the self.
Self-control, moreover, involves more than just avoiding rash choices that will damage one’s future self. It can also mean suppressing some of our base instincts in the service of motives that we are better able to justify. Sneaky laboratory techniques, such as measurements of how quickly people associate white and black faces with words like good and bad, and neuroimaging experiments that monitor activity in the amygdala, have shown that many white people have small, visceral negative reactions to African Americans.218 Yet the sea change in explicit attitudes toward African Americans that we saw in figures 7–6, 7–7, and 7–8, and the obvious comity with which whites and blacks live and work with each other today, show that people can allow their better judgments to overcome these biases.
Reasoning can also interact with the moral sense. Each of the four relational models from which moral impulses spring comes with a particular style of reasoning. Each of these modes of reasoning may be matched with a mathematical scale, and each is implemented by a distinctive family of cognitive intuitions.219 Communal Sharing thinks in all-or-none categories (also called a nominal scale): a person is either in the hallowed group or out of it. The cognitive mindset is that of intuitive biology, with its pure essences and potential contaminants. Authority Ranking uses an ordinal scale: the linear ranking of a dominance hierarchy. Its cognitive gadget is an intuitive physics of space, force, and time: higher-ranking people are deemed bigger, stronger, higher, and first in the series. Equality Matching is measured on a scale of intervals, which allows two quantities to be compared to see which is larger but not entered into proportions. It reckons by concrete procedures such as lining things up, counting them off, or comparing them with a balance scale. Only Market Pricing (and the Rational-Legal mindset of which it is part) allows one to reason in terms of proportionality. The Rational-Legal model requires the nonintuitive tools of symbolic mathematics, such as fractions, percentages, and exponentiation. And as I have mentioned, it is far from universal, and depends on the cognition-enhancing skills of literacy and numeracy.
It’s no coincidence that the word proportionality has a moral as well as a mathematical sense. Only preachers and pop singers profess that violence will someday vanish off the face of the earth. A measured degree of violence, even if only held in reserve, will always be necessary in the form of police forces and armies to deter predation or to incapacitate those who cannot be deterred. Yet there is a vast difference between the minimal violence necessary to prevent greater violence and the bolts of fury that an uncalibrated mind is likely to deliver in acts of rough justice. A coarse sense of tit-for-tat payback, especially with the thumb of self-serving biases on the scale, produces many kinds of excess violence, including cruel and unusual punishments, savage beatings of naughty children, destructive retaliatory strikes in war, lethal reprisals for trivial insults, and brutal repression of rebellions by crappy governments in the developing world. By the same token, many moral advances have consisted not of eschewing force across the board but of applying it in carefully measured doses. Some examples include the reform of criminal punishment following Beccaria’s utilitarian arguments, the measured punishments of children by enlightened parents, civil disobedience and passive resistance that stop just short of violence, the calibrated responses to provocations by modern democracies (military exercises, warning shots, surgical strikes on military installations), and the partial amnesties in postconflict conciliation. These reductions in violence required a sense of proportionality, a habit of mind that does not come naturally and must be cultivated by reason.
Reason can also be a force against violence when it abstracts violence itself as a mental category and construes it as a problem to be solved rather than a contest to be won. The Greeks of Homer conceived of their devastating wars as the handiwork of sadistic puppeteers on high.220 That, to be sure, required a feat of abstraction: they lifted themselves out of a vantage point from which war is the fault of one’s eternally treacherous enemies. Yet blaming the gods for war does not open up many practical opportunities for mere mortals to reduce it. Moralistic denunciations of war also single it out as an entity, but they provide few guidelines on what to do when an invading army is at one’s doorstep. A real change came in the writings of Grotius, Hobbes, Kant, and other modern thinkers: war was intellectualized as a game-theoretic problem, to be solved by proactive institutional arrangements. Centuries later some of these arrangements, such as Kant’s triad of democratization, trade, and an international community, helped to drive down the rate of war in the Long Peace and the New Peace. And the Cuban Missile Crisis was defused when Kennedy and Khrushchev consciously reframed it as a trap for the two of them to escape without either side losing face.
None of these rationales for rationality speaks to Hume’s point that rationality is merely a means to an end, and that the end depends on the thinker’s passions. Reason can lay out a road map to peace and harmony, if the reasoner wants peac
e and harmony. But it can also lay out a road map to war and strife, if the reasoner delights in war and strife. Do we have any reason to expect that rationality should orient a reasoner to wanting less violence?
On the grounds of austere logic, the answer is no. But it doesn’t take much to switch it to yes. All you need are two conditions. The first is that the reasoners care about their own well-being: that they prefer to live rather than die, keep their body parts intact rather than have them maimed, and spend their days in comfort rather than in pain. Mere logic does not force them to have those prejudices. Yet any product of natural selection—indeed, any agent that manages to endure the ravages of entropy long enough to be reasoning in the first place—will in all likelihood have them.
The second condition is that the reasoners be part of a community of other agents who can impinge on their well-being and who can exchange messages and comprehend each other’s reasoning. That assumption too is not logically necessary. One could imagine a Robinson Crusoe who reasons in solitude, or a Galactic Overlord who is untouchable by his subjects. But natural selection could not have manufactured a solitary reasoner, because evolution works on populations, and Homo sapiens in particular is not just a rational animal but a social and language-using one. As for the Overlord, uneasy lies the head that wears a crown. Even he, in principle, must worry about the possibility of a fall from power that would require him to deal with his erstwhile underlings.
As we saw at the end of chapter 4, the assumptions of self-interest and sociality combine with reason to lay out a morality in which nonviolence is a goal. Violence is a Prisoner’s Dilemma in which either side can profit by preying on the other, but both are better off if neither one tries, since mutual predation leaves each side bruised and bloodied if not dead. In the game theorist’s definition of the dilemma, the two sides are not allowed to talk, and even if they were, they would have no grounds for trusting each other. But in real life people can confer, and they can bind their promises with emotional, social, or legal guarantors. And as soon as one side tries to prevail on the other not to injure him, he has no choice but to commit himself not to injure the other side either. As soon as he says, “It’s bad for you to hurt me,” he’s committed to “It’s bad for me to hurt you,” since logic cannot tell the difference between “me” and “you.” (After all, their meaning switches with every turn in the conversation.) As the philosopher William Godwin put it, “What magic is there in the pronoun ‘my’ that should justify us in overturning the decisions of impartial truth?”221 Nor can reason distinguish between Mike and Dave, or Lisa and Amy, or any other set of individuals, because as far as logic is concerned, they’re just a bunch of x’s and y’s. So as soon as you try to persuade someone to avoid harming you by appealing to reasons why he shouldn’t, you’re sucked into a commitment to the avoidance of harm as a general goal. And to the extent that you pride yourself on the quality of your reason, work to apply it far and wide, and use it to persuade others, you will be forced to deploy that reason in pursuit of universal interests, including an avoidance of violence.222
Humans, of course, were not created in a state of Original Reason. We descended from apes, spent hundreds of millennia in small bands, and evolved our cognitive processes in the service of hunting, gathering, and socializing. Only gradually, with the appearance of literacy, cities, and long-distance travel and communication, could our ancestors cultivate the faculty of reason and apply it to a broader range of concerns, a process that is still ongoing. One would expect that as collective rationality is honed over the ages, it will progressively whittle away at the shortsighted and hot-blooded impulses toward violence, and force us to treat a greater number of rational agents as we would have them treat us.
Our cognitive faculties need not have evolved to go in this direction. But once you have an open-ended reasoning system, even if it evolved for mundane problems like preparing food and securing alliances, you can’t keep it from entertaining propositions that are consequences of other propositions. When you acquired your mother tongue and came to understand This is the cat that killed the rat, nothing could prevent you from understanding This is the rat that ate the malt. When you learned how to add 37 + 24, nothing could prevent you from deriving the sum of 32 + 47. Cognitive scientists call this feat systematicity and attribute it to the combinatorial power of the neural systems that underlie language and reasoning.223 So if the members of species have the power to reason with one another, and enough opportunities to exercise that power, sooner or later they will stumble upon the mutual benefits of nonviolence and other forms of reciprocal consideration, and apply them more and more broadly.
This is the theory of the expanding circle as Peter Singer originally formulated it.224 Though I have co-opted his metaphor as a name for the historical process in which increased opportunities for perspective-taking led to sympathy for more diverse groups of people, Singer himself did not have the emotions in mind so much as the intellect. He is a philosopher’s philosopher, and argued that over the aeons people had the power to literally think their way into greater respect for the interests of others. And that respect cannot be confined to the interests of the people with whom we rub shoulders in a small social circle. Just as you can’t favor yourself over someone else when holding up ideals on how to behave, you can’t favor members of your group over the members of another group. For Singer, it is hardheaded reason more than softhearted empathy that expands the ethical circle ever outward:Beginning to reason is like stepping onto an escalator that leads upward and out of sight. Once we take the first step, the distance to be traveled is independent of our will and we cannot know in advance where we shall end....
If we do not understand what an escalator is, we might get on it intending to go a few meters, only to find that once we are on, it is difficult to avoid going all the way to the end. Similarly, once reasoning has got started it is hard to tell where it will stop. The idea of a disinterested defense of one’s conduct emerges because of the social nature of human beings and the requirements of group living, but in the thought of reasoning beings, it takes on a logic of its own which leads to its extension beyond the bounds of the group.225
In the historical sequence that Singer adduces, the moral circle of the early Greeks was confined to the city-state, as in this unintentionally comical epitaph from the mid-5th century CE:This memorial is set over the body of a very good man. Pythion, from Megara, slew seven men and broke off seven spear points in their bodies.... This man, who saved three Athenian regiments . . . having brought sorrow to no one among all men who dwell on earth, went down to the underworld felicitated in the eyes of all.226
Plato widened the circle a bit by arguing that Greeks should spare other Greeks from devastation and enslavement, visiting these fates only on non-Greeks. In modern times Europeans expanded the no-taking-slaves rule to other Europeans, but Africans were fair game. Today, of course, slavery is illegal for everyone.
The only problem with Singer’s metaphor is that the history of moral concern looks less like an escalator than an elevator that gets stuck on a floor for a seeming eternity, then lurches up to the next floor, gets stuck there for a while, and so on. Singer’s history finds just four circle sizes in almost two and a half millennia, which works out to one ascent every 625 years. That feels a bit jerky for an escalator. Singer acknowledges the bumpiness of moral progress and attributes it to the rarity of great thinkers:Insofar as the timing and success of the emergence of a questioning spirit is concerned, history is a chronicle of accidents. Nevertheless, if reasoning flourishes within the confines of customary morality, progress in the long run is not accidental. From time to time, outstanding thinkers will emerge who are troubled by the boundaries that custom places on their reasoning, for it is in the nature of reasoning that it dislikes notices saying “off limits.” Reasoning is inherently expansionist. It seeks universal application. Unless crushed by countervailing forces, each new application will become part of the territory of
reasoning bequeathed to future generations.227
But it remains puzzling that these outstanding thinkers have appeared so rarely on the world’s stage, and that the expansion of reason should have dawdled so. Why did human rationality need thousands of years to arrive at the conclusion that something might be a wee bit wrong with slavery? Or with beating children, raping unattached women, exterminating native peoples, imprisoning homosexuals, or waging wars to assuage the injured vanity of kings? It shouldn’t take an Einstein to figure it out.
One possibility is that the theory of an escalator of reason is historically incorrect, and that humanity was led up the incline of moral progress by the heart rather than the head. A different possibility is that Singer is right, at least in part, but the escalator is powered not just by the sporadic appearance of outstanding thinkers but by a rise in the quality of everyone’s thinking. Perhaps we’re getting better because we’re getting smarter.
Believe it or not, we are getting smarter. In the early 1980s the philosopher James Flynn had a Eureka! moment when he noticed that the companies that sell IQ tests periodically renorm the scores.228 The average IQ has to be 100 by definition, but the percentage of questions answered correctly is an arbitrary number that depends on how hard the questions are. The testmongers have to map the percentage-correct scale onto the IQ scale by a formula, but the formula kept getting out of whack. The average scores on the tests had been creeping up for decades, so to keep the average at 100, every once in a while they jiggered the formula so the test-takers would need a larger number of correct answers to earn a given IQ. Otherwise there would be IQ inflation.