Moral Tribes: Emotion, Reason, and the Gap Between Us and Them
by joshua greene
penguin, 432 pages, $29.95

Joshua Greene’s Moral Tribes is a book about the origins of our moral disagreements and how to overcome them. Greene, who directs the Moral Cognition Lab at Harvard University, presents the reader with an accessible account of recent work on the psychology of moral judgment. This research, he argues, not only explains our deepest moral disputes, but also reveals a rational standard that we can use to resolve them. In a culture that is both painfully riven by moral disagreement and greatly impressed by the achievements of science, this is an enticing proposition.

Greene’s proposal is that we should do whatever maximizes happiness. Everyone’s happiness should be treated as equally valuable, and the impartiality of this principle will make it suitable for overcoming the tribalism that leads us to favor the interests of members of our own group over those of outsiders. Agreement at the level of general principle would not guarantee complete agreement on moral issues, but any remaining disputes would concern empirical claims about what would do the most to promote happiness. “Public moral debate should be a lot wonkier,” Greene argues.

The claim that we should maximize happiness impartially is not itself new. It is a concise summary of the utilitarian approach to morality, which already exerts considerable influence in public debate. The originality of Greene’s proposal lies not in the principle that he advocates, but in his argument that moral psychology discredits both rival ­theories and the moral intuitions that are commonly appealed to by critics who argue that utilitarianism cannot be the right theory of morality because it gets the answers wrong.

Greene begins by offering an evolutionary account of the development of morality. Morality, he says, evolved as a mechanism for promoting cooperation within groups but competition between groups (the optimal strategy from an evolutionary point of view). The morality that we have inherited is well matched to the demands of the lives of tribal hunter-gatherers, but ill fitted to the challenges of our modern world, in which we need to secure ­cooperation between groups, including groups with widely divergent cultures and values.

The early chapters of the book also discuss a variety of empirical studies of the biases that affect our moral thinking. For example, we have a strong tendency to interpret the requirements of fairness in ways that will favor our interests while sincerely believing that we are being impartial.

When stated that plainly, this sounds like very old news. In the ­Second Book of Samuel, Nathan tells David a parable in which a rich man steals a poor man’s sole possession, a beloved lamb. Nathan waits until David has passed his stern judgment before revealing—“Thou art the man”—that it is David’s own sins to which the parable refers.

The point of confronting David in this way has never been hard to grasp, but while it is not a new discovery that our sense of justice is in­fluenced by our self-interest, systematic study has revealed that its effects are far more pervasive than commonly recognized. It is a disturbing but ­valuable lesson. While it does not prove that when our moral judgments are at odds with utilitarianism those judgments are in error, it does give us cause to second-guess them.

Greene is best known for developing a “dual-process” theory of moral cognition according to which our moral thinking involves two distinct and separate processes. According to him, when we think about morality, our brain functions like a dual-mode camera with both automatic and manual ­settings. Each mode has its advantages and disadvantages: The automatic settings are convenient and work well when taking pictures under normal conditions, whereas the manual settings require more time and effort but produce better results in unusual situations.

Our moral emotions and in­tui­tions are the brain’s automatic settings, while our rational deliberation and calculation are its manual mode. The problem is that our gut reactions developed not to promote the good of all, but to support the survival of our own tribes in contexts very different from those in which we now live.

Utilitarian moral thinking is not vulnerable to such concerns because it relies not on instinct but on calculation. This makes it, in Greene’s view, “the native philosophy of the human manual mode.” Figuring out how to bring about the maximum possible amount of happiness is an exercise in cost-benefit analysis, a paradigm case of rational decision making.

Greene’s argument fails because it confuses the rationality of ­applying the utilitarian principle with the ­rationality of accepting that principle in the first place. The fact that one can pursue a goal rationally does not show that it is rational to adopt it as a goal. Greene is by no means ­unusual in eliding this distinction. Insofar as the appeal of utilitarianism derives from the sense that it represents a rational approach to morality, its appeal has always depended on this elision.

The arguments against utili­tarianism are not limited to appeals to our intuitions. The theory also faces competition from other schools of ethical thought, and any defense of utilitarianism needs to offer a reason to prefer the theory over its rivals. Greene adopts the audacious strategy of arguing that all the major non-utilitarian ethical theories derive from attempts to rationalize our moral intuitions.

He claims that utilitarianism has two major rivals, virtue ethics and deontology, ­represented by Aristotle and Kant respectively. He portrays Aristotle as nothing more than a tribal philosopher who codifies the ethos of his city and class. On this view, ­Aristotle’s ethics simply describe “what it means to be a wise and temperate Macedonian-Athenian aristocratic man.” This ignores the fact that while ­Aristotle frequently begins his ethical inquiries by surveying commonly held beliefs, he does so in order to subject those beliefs to philosophical scrutiny and often arrives at conclusions that do not reflect the conventional wisdom of his time and place. Aristotle was a philosopher, not just an anthropologist cataloging the ­mores of his own tribe.

The treatment of Kant is no better. Greene sees Kant’s moral philosophy as nothing but a sophisticated rationalization of the common sense of his tribe (Greene does not specify which tribe he has in mind). He rejects Kant’s test of universalizability on the grounds that being fashionable cannot be universalized (if everyone is fashionable, then no one is), and yet being fashionable is not immoral. This objection misses the point that the test of universalizability applies to principles of action, which Kant calls maxims. Someone who dresses fashionably need not be acting on a principle that would, if universalized, require everyone to dress fashionably. Here as elsewhere, Greene’s criticism reveals an elementary misunderstanding of the theory that he is attacking.

That Greene’s blithe dismissals of Aristotle and Kant occupy only a few pages does not make them less culpable. Even sympathetic readers may wonder if it could be quite that simple to show that utilitarianism’s rivals are nothing more than auto-ethnography or, at best, rationalizations of our gut reactions. The reason Greene’s refutations are so perfunctory is that he does not regard utilitarianism as having serious rivals at all. For him it is a sine qua non of an acceptable moral theory that it can provide the basis for moral consensus, and he thinks that utilitarianism is the only theory that could serve that purpose. The long and illustrious history of Aristo­telianism and Kantianism is an indictment against both theories: If they were capable of producing a consensus, they would have done so by now.

Utilitarianism is supposed to provide a way to reach agreement because our disputes can be resolved empirically; we just have to gather the evidence about which rule or policy will produce the most happiness. It is hard to reconcile Greene’s optimism about data-driven wonkiness with his earlier insistence that we are prone to assess evidence in ways that reinforce our pre-existing attitudes and beliefs. The way that “studies” are employed in our public debates confounds his suggestion that if only we focused on empirical data we would be able to achieve consensus.

So Greene’s case for utilitarianism fails on its own terms, but they were the wrong terms in any case. We cannot agree to a moral principle just because doing so would spare us the acrimony of disagreement. What the utilitarian needs and what Greene fails to provide is not evidence that by applying utilitarian cost-benefit analysis we could arrive at the same answer, but a good reason to believe that it would be the right answer.  

Peter Wicks teaches in the ethics program at Villanova University.

Articles by Peter Wicks