9 The neuroscience of ethics In the preceding chapters, we considered difficult questions con- cerning the ethical permissibility or desirability of various ways of intervening into the minds of human beings. In examining these questions, we took for granted the reliability of the ethical theories, principles and judgments to which we appealed. But some thinkers have argued that the sciences of the mind are gradually revealing that we cannot continue to do so. Neuroscience and social psy- chology, these thinkers claim, show that our ethical judgments are often, perhaps even always, unjustified or irrational. These sci- ences are stripping away the layers of illusion and falsehood with which ethics has always clothed itself. What lies beneath these illusions? Here thinkers diverge. Some argue for a revisionist view, according to which the lesson of the sciences of the mind is that all moral theories but one are irrational; on this revisionist view, the sciences of the mind provide decisive support for one particular ethical theory. Some argue for an eliminativist view, according to which the sciences of the mind show that all moral theories and judgments are unjustified. In this chapter, we shall assess these twin challenges. How is this deflation of morality supposed to take place? The neuroscientific challenge to ethics focuses upon our intuitions. Neuroscience, its proponents hold, shows that our moral intuitions are systematically unreliable, either in general or in some particular circumstances. But if our moral intuitions are systematically unre- liable, then morality is in serious trouble, since moral thought is, at bottom, always based upon moral intuition. Intuitions play different roles, and are differentially prominent, in different theories. But no moral theory can dispense with intuitions altogether. Each owes its appeal, in the final accounting, to the plausibility of one or more robust intuitions. Understanding the ways in which the assault on ethics is supposed to work will therefore require understanding the role of intuitions in ethical thought. ethics and intuitions Many moral philosophers subscribe to the view of moral thought and argument influentially defended by John Rawls (1971). Rawls argued that we test and justify moral theories by seeking what he called reflective equilibrium between our intuitions and our explicit the- ories. What, however, is an intuition? There is no universally accepted definition in the literature. Some philosophers identify intuitions with intellectual seemings: an irrevocable impression forced upon us by consideration of a circumstance, which may or may not cause us to form the corresponding belief – something akin to a visual seeming, which normally causes a belief, but which may sometimes be dismissed as an illusion (Bealer 1998). Consider, for example, the intuition provoked by a famous demonstration of the conjunction fallacy (Tversky and Kahneman 1983). In this experiment, subjects were required to read the fol- lowing description: Linda is thirty-one years old, single, outspoken, and very bright. She majored in philosophy. As a student, she was deeply concerned with issues of discrimination and social justice, and also participated in anti-nuclear demonstrations. Subjects were then asked to rank a list of statements about Linda in order of their probability of being true, from most to least likely. The original experiment used eight statements, but five of them were filler. The three statements of interest to the experimenters were the following: (1) Linda is active in the feminist movement. (2) Linda is a bank teller. (3) Linda is a bank teller and is active in the feminist movement. the neuroscience of ethics 282 A large majority of subjects ranked statement (3) as more probable than statement (2). But this can’t be right; (3) can’t be more probable than (2) since (3) can be true only if (2) is true as well. A conjunction of two propositions cannot be more likely than either of its conjuncts (indeed, conjunctions are usually less probable than their conjuncts). Now, even after the conjunction fallacy is explained to people, and they accept its truth, it may nevertheless go on seeming as if – intellectually seeming – (3) is more probable than (2). Even someone as mathematically sophisticated as Steven Jay Gould was vulnerable to the experience: I know that the third statement is least probable, yet a little homunculus in my head continues to jump up and down, shouting at me–‘but she can’t just be a bank teller; read the description.’ (Gould 1988) In other words, the description provokes in us an intellectual seeming, an intuition, which we may then go on to accept or – as in this case, though much less often – to reject. There is some controversy about this definition of intuitions, but it will suffice for our purposes. In what follows, I shall identify intuitions with spontaneous intellectual seemings. Intuitions are spontaneous in the sense that they arise unbidden as soon as we consider the cases that provoke them. They are also, typically, stub- born: once we have them they are relatively hard to shift. Intuitions may be given up as false after reflection and debate, but even then we do not usually lose them, not, at least, all at once. In moral thought, intuitions are often characterized as ‘‘gut feel- ings.’’ This is slightly misleading, inasmuch as it might be taken to suggest that intuitions are lacking in cognitive content. But it does capture the extent to which moral intuitions (especially) are indeed typically deeply affective. Contemplating (say) the events at Abu Ghraib, or the execution of a hostage in Iraq, the indignation I feel powerfully expresses and reinforces my moral condemnation of the actions. For many other scenarios, real and imaginary, which I judge to ethics and intuitions 283 be wrong, the affective response is much weaker, so much weaker that I may not even be conscious of it. However, as Damasio’s work on somatic markers indicates, it is likely that even in these cases my judgment is guided by my somatic responses: measurements of my skin conductance, heart rate and other autonomic systems, would probably indicate heightened activity, of precisely the kind involved in affective responses. Many, if not all, moral intuitions should be considered both cognitive and affective, with the affective component having a powerful tendency to cause or to reinforce the corresponding belief. To intuit that an act is right (wrong) is not, however, neces- sarily to go on to form the belief that the act is right (wrong). It’s quite possible for people to have moral intuitions which do not correspond to their moral beliefs (just as we can experience an optical illusion, in the full knowledge that it is an illusion). Nevertheless, moral intui- tions are normally taken to have very strong evidential value. An intuition normally causes the corresponding belief, unless the agent has special reason to think that their intuition is, on this occasion, likely to be unreliable. Intuitions are usually taken to have justifi- catory force, and, as a matter of fact, typically lead to the formation of beliefs that correspond to them. Intuitions play an important role in many, perhaps most, areas of enquiry. But they are especially central to moral thought. Accord- ing to Rawls, we test a moral theory by judging the extent to which it accords with our intuitions (or our considered moral judgments – we shall consider possible differences between them shortly). Theory construction might begin, for instance, by simply noting our intuitive responses to a range of uncontroversial moral cases, and then making a first attempt at systematizing them by postulating an overarching principle that apparently explains them all. Thus, we might begin with judgments that are overwhelmingly intuitive, like the following: It is wrong to torture babies for fun; Giving to charity is usually praiseworthy; Stealing, lying and cheating are almost always wrong. the neuroscience of ethics 284 What principle might explain all these judgments? One possibility is a simple utilitarian principle, such as the principle formulated by Jeremy Bentham, the father of utilitarianism. According to Bentham, it is ‘‘the greatest happiness of the greatest number that is the measure of right and wrong;’’ that is, an action is right when it produces more happiness for more people than any alternative. It is therefore wrong to torture babies because the harm it causes them is so great; giving to charity is right, on the other hand, because it tends to increase happiness. Once we have our moral principle in hand, we can test it by attempting to formulate counterexamples. Typically, a good counterexample is a case, real or imaginary, in which an action is wrong – intuitively wrong – even though it does not violate the moral principle under examination. If we can discover such a counter- example, we have (apparently) shown that the moral principle is false. Our principle is not, after all, in harmony with our intuitions, and therefore we have not yet reached reflective equilibrium. Are there counterexamples to Bentham’s simple utilitarian principle? Plenty. There are many cases, some of them all too real, in which an action which maximizes happiness nevertheless seems to be wrong. Indeed, even actions like torturing babies for fun could turn out to be mandated by the principle. Suppose that a group of people is so constituted that they will get a great deal of pleasure out of seeing a baby tortured. The pain caused to the baby might be outweighed by the pleasure it causes the onlookers, especially if there are very many of them and they experience a great deal of pleasure. In response to counterexamples like this, we continue the search for reflective equilibrium by refining our moral principles to try to bring them into harmony with our intuitions. For instance, we might look to a more sophisticated consequentialist principle – that is, a principle that, like Bentham’s, bases judgments of right or wrong on the consequences of actions. Alternatively, we might look to a deontological principle, according to which people have rights which must not be violated – such as the right to freedom from torture – no ethics and intuitions 285 matter the consequences. Mixed theories, and character-based theories, have also been developed by many thinkers. The search for reflective equilibrium is therefore the search for a principle or set of principles that harmonizes, and presumably underlies, our intuitions, in much the same way as the search for grammatical rules is (according to many linguists) the making explicit of rules that competent language users employ implicitly. However, though intuitions guide this search, they are not taken to be sacrosanct by proponents of reflective equilibrium. It may be that a moral principle is itself so intuitively plausible that when it con- flicts with a single-case intuition, we ought to keep the principle rather than modify it. Moreover, intuitions may be amenable to change, at least at the margins; we may find that our intuitions gradually fall into line with our moral theory. Even if they don’t, it may be that we ought to put up with a certain degree of disharmony. The conjunction fallacy is obviously a fallacy: reflection on it, as well as probability theory, confirms this. We should continue to regard it as a fallacy no matter the degree of conflict with our intuitions in cases like ‘‘Linda the bank teller.’’ Similarly, it may be that the best moral theory will clash with some of our moral intuitions. Never- theless – and this is the important point here – moral theory con- struction begins from, and continues indispensably to refer to, our moral intuitions from first till (almost) the last. The best moral theory will systematize a great many of our moral intuitions; ideally it will itself be intuitive, at least on reflection. Some theorists seek to avoid reliance on intuitions. One way they have sought to do so is by referring, in the process of attempting to reach reflective equilibrium, not to intuitions but to ‘‘considered moral judgments’’ instead. This tack won’t work: if considered moral judgments are something different to intuitions – in some philoso- phers’ work, they seem to be much the same thing – then we can only reach them via intuitions. If they are not intuitions, then our considered moral judgments are nothing more than the judgments we reach after we have already begun to test our intuitions against the neuroscience of ethics 286 our moral principles; in other words, when our judgments have already reached a (provisional) harmony with a moral principle. Some utilitarians, such as Peter Singer (1974), suggest that their preferred moral theory avoids reliance on intuitions altogether. They reject intuitions as irrational prejudices, or the products of cultural indoc- trination. However, it is apparent – as indeed our first sketch of a justification for utilitarianism made clear – that utilitarianism itself is just as reliant upon intuitions as is any other moral theory (Daniels 2003). Singer suggests that we reject intuitions in favor of ‘‘self-evident moral axioms’’ (1974: 516). But self-evidence is itself intuitiveness, of a certain type: an axiom is self-evident (for an individual) if that axiom seems true to that individual and their intuition in favor of that axiom is undefeated. Hence, appeal to self- evidence just is appeal to intuition. The great attraction of utilitarianism rests upon the intuitive- ness of a principle like Bentham’s, which rests, itself, on the intui- tiveness of the claim that pains and pleasures are, respectively and ceteris paribus, good and bad. No moral theory seems likely to be able to dispense with intuitions, though different theories appeal to them in different ways. Some give greater weight to case-by-case intuitions, as deontologists may do, and as everyday moral thought seems to (DePaul 1998). Others, like utilitarianism, rest the justifi- catory case on one big intuition, a particular moral principle taken to be itself so intuitive that it outweighs case-by-case intuitions (Pust 2000). Whatever the role intuitions play in justifying their principles or their case-by-case judgments, all moral theories seem to be based ultimately upon moral intuition. It is this apparently indispensable reliance of moral reflection upon intuition that leaves it open to the challenges examined here. In a sense, these challenges build upon Singer’s (indeed, we shall see that Singer himself has seized upon them as evidence for his view): they provide, or are seen as providing, evidence for the claim that intuitions are indeed irrational. But in its more radical form, the challenge turns against consequentialism, in all its varieties, just as ethics and intuitions 287 much as rival moral theories: if our intuitions are systematically unreliable guides to moral truths, if they fail to track genuine, or genuinely moral, features of the world, then all moral theories are in deep trouble. the neuroscientific challenge to morality There are many possible challenges to our moral intuitions, and thence to the rationality of moral judgments. They come, for instance, from psychology (Horowitz 1998) and from evolutionary considerations (Joyce 2001; 2006). These challenges all take a similar form: they adduce evidence for the claim that our intuitions are prompted by features of our mind/brain that, whatever else can be said for them, cannot be taken to be reliable guides to moral reality. Here I shall focus on two versions of this challenge to our intuitions, an argument from neuroscience, and an argument from social psy- chology. First, the argument from neuroscience. In a groundbreaking study of the way in which brains process moral dilemmas, Joshua Greene and his colleagues found significant differences in the neural processes of subjects, depending upon whether they were considering personal or impersonal moral dilemmas (Greene et al. 2001). A personal moral dilemma is a case which involves directly causing harm or death to someone, whereas an impersonal moral dilemma is a case in which harm or death results from less direct processes. For instance, Greene and collea- gues used variations on the famous trolley problem (also considered in Chapter 5) as test dilemmas. The first version of this problem is an impersonal variant of the dilemma, whereas the second is a personal variant: (1) Imagine you are standing next to railway tracks, when you see an out-of-control trolley hurtling towards you. If the trolley continues on its current path, it will certainly hit and kill five workers who are in a nearby tunnel. You cannot warn them in time, and they cannot escape from the tunnel. However, if you pull a lever you can divert the trolley to a sidetrack, where it will certainly hit and kill a single the neuroscience of ethics 288 worker. Assume you have no other options available to you that would save the five men. Should you pull the lever? (2) Imagine that this time you find yourself on a bridge over the railway tracks when you see the trolley hurtling toward a group of five workers. The only way to prevent their certain deaths is for you to push the fat man standing next to you into its path; this will stop the trolley, but the man will die. It’s no use you leaping into its path; you are too light to stop the trolley. Should you push the fat man? The judgments of Greene’s subjects were in line with those of most philosophers: the great majority judged that in the first case it is permissible or even obligatory to pull the lever, but in the second it is impermissible to push the fat man. Now, from some angles these judgments are prima facie inconsistent. After all, there is a level of description – well captured by consequentialism – in which these cases seem closely similar in their morally relevant features. In both, the subject is asked whether he or she should save five lives at the cost of one. Yet most people have quite different intuitions with regard to the two cases: in the first, they think it is right to save the five, but in the second they believe it to be wrong. Most philosophers have responded to these cases in the tradi- tional way described by Rawls: they have sought a deeper moral principle that would harmonize their intuitions. For instance, the following Kantian principle has been suggested: it is wrong to use people as a means to others’ ends. The idea is this: in pushing the fat man into the path of the trolley, one is using him as a means whereby to prevent harm to others, since it is his bulk that will stop the trolley. But in pulling the lever one is not using the man on the tracks as a means, since his presence is not necessary to saving the lives of the five. Pulling the lever would work just as well if he were absent, so we do not use him. Unfortunately, this suggestion fails. Consider the looping track variant of the problem (Thomson 1986). In this variant, pulling the lever diverts the trolley onto the alternative track, but that track loops back onto the initial track, in such a the neuroscientific challenge to morality 289 manner that were it not for the presence of the solitary worker, the trolley would end up killing the five anyway. In that case, diverting the trolley saves the five, but only by using the one worker as a means: were it not for his presence, the strategy wouldn’t work. Nevertheless, most people have the intuition that it is permissible to pull the lever. Greene and colleagues claim that their results cast a radically different light on these dilemmas. They found that when subjects considered impersonal dilemmas, regions of the brain associated with working memory showed a significant degree of activation, while regions associated with emotion showed little activation. But when subjects considered personal moral dilemmas, regions asso- ciated with emotion showed a significant degree of activity, whereas regions associated with working memory showed a degree of activity below the resting baseline (Greene et al. 2001). Why? The authors plausibly suggest that the thought of directly killing someone is much more personally engaging than is the thought of failing to help someone, or using indirect means to harm them. In their original study Greene and his co-authors explicitly deny that their results have any direct moral relevance. Their con- clusion is ‘‘descriptive rather than prescriptive’’ (2001: 2107). How- ever, it is easy to see how their findings might be taken to threaten the evidential value of our moral intuitions. It might be suggested that the high degree of emotional involvement in the personal moral dilemmas clouds the judgment of subjects. It is, after all, common- place that strong emotions can distort our judgments. Perhaps the idea that the subjects would themselves directly cause the death of a bystander generates especially strong emotions, which cause them to judge irrationally in these cases. Evidence for this suspicion is provided by the under-activation of regions of the brain associated with working memory. Perhaps subjects do not properly think through these dilemmas. Rather, their distaste for the idea of killing prevents them from rationally considering these cases at all (Sinnott- Armstrong 2006). the neuroscience of ethics 290 [...]... consist, arguably, in the cooperative dispositions of creatures as primitive as predatory fish and the much smaller fish which clean them These fish are often the right size to make a good meal for the predators Yet the latter do not attempt to eat the cleaners; instead, they seek them out, and when they locate them go into a kind of trance while the smaller fish removes parasites from them The small fish sometimes... inside the mouths of the larger, and out their gills, in their search for the parasites, without being threatened Why? The answer seems to be because ancestors of these predators who accepted cleaning services and then made a meal of the cleaners were outperformed by those who returned to the same spot many times, to have their parasites removed again The benefits of regular parasite removal outweigh the. .. find further evidence of the irrationality of intuitions in psychology; specifically in the work of Jonathan Haidt, the source of the second challenge to morality we shall examine here Over the past decade, Haidt (2001; 2003; Haidt et al 1993) has been developing what he calls the social intuitionist model (SIM) of moral judgments The model has two components: the first component centres upon the processes... explaining the significant political changes in all Western, as well as many non-Western, societies over the past two centuries, from the abolition of (legal) slavery in the nineteenth century, to the enfranchisement of women in the twentieth and the gradual move toward the full recognition of the humanity of homosexuals It is also, I speculate, a process that is still underway Recent research on the role of. .. more often with strangers than with relatives, we have the feeling of universal benevolence Of course, the story I have just told is somewhat speculative But the evidence that universal benevolence has evolved is plentiful It consists, once again, in the proto-moral behavior of other animals Other social animals exhibit a concern for conspecifics, independent of their degree of relatedness or of opportunities... profess The view of moral facts as existing independently of us is non-naturalist: it takes morality to be somehow part of the furniture of the universe, in some manner independent of the kinds of entities science investigates In some versions it is a Platonism, holding that moral facts belong to a sui generis category, equally (or more) real as the observable world, but irreducible to them; in others... can then be disseminated, in the ways that knowledge usually is; when it is transferred not as blind dogma, but as the product, always somewhat tentative and open to revision, of a distributed cognitive enterprise, we also transfer the warrant for the belief Most of us, most of the time, will be able to articulate very little in the way of explicit justification for most of our beliefs They are none the. .. reflect on their intuitions and their moral theories, and – typically – exposure to a wider range of moral views Their intuitions ought to be granted an accordingly greater weight distributed cognition: extending the moral mind We began this book by examining the plausibility of the extended mind hypothesis I advanced evidence that I took to support the hypothesis, but I also suggested that nothing of great... formed; the second centres on their rationality The process claim is that moral judgments are the product of intuition, not reasoning: certain situations evoke affective responses in us, which give rise to (or perhaps just are) moral intuitions, which we then express as moral judgments The rationality claim is that since moral judgments are the product of emotions, they neither are the product of rational... to rational correction, but the differential responses of higher and lower SES subjects demonstrates that in fact moral intuitions are amenable to education The greater the length of formal education, the less the likelihood of subjects holding that victimless transgressions are morally wrong (the effect of SES on the moral judgment of children is, accordingly, less than the effect on adults (Haidt . himself to find further evidence of the irrationality of intuitions in psychology; specifically in the work of Jonathan Haidt, the source of the second challenge. speaks of the ‘‘moral dumbfounding’’ he encounters, when he asks subjects for their reasons for their moral judgments. They laugh, the neuroscience of ethics