Book review |
Rights, wrongs and neurons
In recent years we have seen the arrival of various species, or subdivisions, of ethics: for example, bioethics, medical ethics, professional ethics, research ethics and genethics. Now there is a new addition: neuroethics. Neuroethics, it would seem, has something to do with the brain. The brain is one organ amongst many, and there is already a well-established literature that deals with issues that arise in biomedicine with regard to diagnosis, therapeutic treatment, research, and so on. For example, a few years ago there was a volume in medical ethics entitled Ethics and the Kidney edited by Norman Levinsky (2001)
. The brain, like the kidney, is an organ. So, is neuroethics in the same vein as renal ethics? Is it just a simple part of bioethics? These two recently published books suggest not, albeit in different ways. The Neuroethics volume edited by Judy Illes is a collection of papers by a number of authors from different disciplines, including neuroscience, social science and the law. Gazzaniga's The Ethical Brain is a ‘popular science’ monograph aimed at making some of the core work in neuroethics accessible to a broader audience. In both books there is an assumption, sometimes explicitly argued for, sometimes implicit, that neuroethics marks out a distinctive area for research and public policy. But what exactly is neuroethics? Many of the pieces in the Illes collection cite a useful clarificatory distinction made by Adina Roskies (herself a contributor to the volume) between two things that ‘neuroethics’ might mean. On the one hand, there is the ethics of neuroscience; on the other, the neuroscience of ethics. Issues in the ethics of neuroscience are, by and large, variants of familiar topics in bioethics. There are issues of consent in research ethics; there are issues of privacy with regard to neuroimaging; there are issues about the ethics of ‘enhancing’ people's traits and competences by engineering the brain. Gazzaniga's book and a number of the articles in the Illes collection engage with these issues.
In a short review discussion, however, we cannot fruitfully take in hand the many topics—falling broadly under the heading ‘the ethics of neuroscience’—that are raised and explored in these books. Instead I will address the second branch of neuroethics (also discussed in both books): the neuroscience of ethics. This seems to raise an obvious distinction between, say, renal science and bioethics on the one hand, and neuroscience on the other: there is no comparable sense in which there could be a renal biomedical science of ethics.
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Although a neuroscience of ethics does indeed mark neuroethics out as something distinctive, the very idea may seem puzzling. What can neuroscience tell us about ethics? For a start, is not ethics primarily normative: dealing with what we ought and ought not to do? Neuroscience, by way of contrast, is descriptive. Learning about the structure, function and nature of the brain does not, by itself, tell us anything at all about what ought to be done. So how can there be a neuroscience of ethics at all?
One line of connection between neuroscience and ethics is indirect—via psychology. Ethics is primarily concerned with intentional actions (including so-called ‘negative’ actions like refraining from or refusing to do something). Ethical descriptions of actions deploy normative concepts including explicit ones (right, wrong, obligatory, compulsory, permissible, justified) and other concepts where the normative component is, perhaps, less obvious (vicious, blameworthy, responsible, courageous, shameful, and so on). There are strong connections between many ethical concepts and other non-normative psychological concepts. When we blame someone for an action we also commit ourselves to certain other ideas about the agent's state of mind: the agent was conscious; she knew what she was doing; she had an appropriate degree of control over her behaviour. Relatedly, acts of blame express certain psychological attitudes and such attitudes are, typically, based upon and supported by many more psychological states. In general, moral evaluation and moral judgements essentially involve both the having of, and the ascription of, psychological attitudes.
By itself, this kind of link between ethics and psychology does not tell us much about what the connection between ethics and neuroscience might amount to. Suppose we accept that there are important connections between neuroscience and psychology. We might still worry that there can be no interesting role for neuroscience in ethics. After all, we can and do use ethical and legal concepts without possessing or using any neuroscientific knowledge. This suggests that ethics is independent from neuroscience. Philosophers, theologians, poets and countless others throughout history have engaged in vigorous debates about what, ethically speaking, one ought to do without knowing anything of, or relying on, neuroscience. This is in stark contrast to the connection between ethics and psychology. Normal human beings have a very rich folk psychology, which can be drawn upon in ethical ascriptions and reasoning. Our legal systems have evolved complex and subtle standards—based on our folk psychology—for determining the facts about an agent's state of mind without reliance on neuroscientific evidence. So, although ethics is tightly connected to psychology, the lack of a folk neuroscience comparable to folk psychology might seem to pose an obstacle to neuroscience making a contribution to ethics.
But we should not be too hasty. We have not yet spelled out how neuroscience—perhaps via its connections with psychology—might inform, influence or have implications for ethics (and related normative disciplines like the law). It will help if we consider some examples. As noted above, many ethical concepts are only applicable to responsible agents, who, at the time of acting, were in conscious control of their behaviour. Patricia S. Churchland in her contribution to the Neuroethics volume argues that neurobiology offers us an improved way of understanding what it is to be in control (or out of control). There are good evolutionary reasons to assume that a normally functioning brain will allow a creature to stay ‘in control’ of its behaviour. That is, it will be able to inhibit certain impulses, maintain courses of action in pursuit of goals, differentiate and evaluate long-term versus short-term goals. A creature ‘in control’ of its behaviour must not be needlessly distracted or swayed by emotional arousal. Over the past century, many data have been amassed, from anatomy, lesion studies, neuropharmacology and so on, which suggest that there are a number of different systems, within the brain, all of which are involved in achieving and maintaining this adaptationally important state of ‘being in control’. Churchland suggests that we can think of the state of being in control as a complex ‘volume’ in a ‘multi-dimensional parameter space’ where the various parameters are provided by a (scaled) assessment of the level of activity in a range of systems—e.g. the prefrontal cortex, brainstem and limbic system. On this model there can be all sorts of different ways of being in, or out, of control; and neuroscience might offer us ways of thinking about the contrast between being in, and out of, control that are not beholden to our everyday psychological intuitions.
But what might the ethical significance of such findings be? Unfortunately, Churchland does not—in this context at least—spell this out, except by suggesting that ‘these developments in the biological sciences give rise to difficult but important issues concerning the possible revision and improvement of legal practices’ (p. 15). Another article in the Neuroethics volume, however, does directly address the questions that Churchland leaves unanswered. In ‘Moral and legal responsibility and the new neuroscience’ Stephen J. Morse argues that ‘neuroscience is largely irrelevant’ to ‘ascriptions of moral and legal responsibility’ (p. 34). Morse argues that the conception of control and responsibility that matters for legal purposes is one that is bound up with a folk psychological conception of rationality, where notions like intention, and belief and reasons for action are essential elements. Indeed, on Morse's account, the purpose of the law is essentially bound up with notions like rationality and responsibility, insofar as the law is meant to provide rules which can be taken into account in the reasoning and decision-making of sane, rationally competent agents. Morse thus accepts that there may be a role for neuroscience in legal discussions. Neuroscience is likely to discover ‘much more about the types of conditions that can compromise rationality’ and, as such, ‘may potentially lead to a broadening of current legal excusing and mitigating doctrines’ (p. 40). But, he argues, we will have to be cautious in interpreting such findings. The underlying problem is that of correlating and integrating neuroscientific findings with folk psychological notions of intention, deliberation and rationality. For example, we might wonder how Churchland's multi-dimensional ‘volume’ model of being in control is to be related to our folk psychological understanding of rationality when, in many cases, our folk psychological notion of rationality and intention is readily deployed historically (indeed, in the legal context this is essential when the issue to be settled is whether some party can properly be held responsible and justly punished for some past action). Unless the neuroimaging was taking place at the time of the crime, the prosecution might well argue that if folk psychological evidence suggests that the person was in control at the time of action, then later neuroscientific evidence might not be conclusive. Such evidence might, of course, identify a broad structural abnormality or anomaly of the agent's cognitive functioning; and it might then be submitted that it would be reasonable to assume that such a structural anomaly would have been likely to undermine the agent's capacity for control on the (historical) occasion in question, but there does not seem to be—as of yet—any clear suggestion as to how one would settle conflicts between folk psychological and neuroscientific evidence.
This does not imply that progress is not possible. But Morse is, I think, right to stress the need for caution here. He is also right to point out that the debate about legal responsibility has almost nothing to do with the metaphysical debate about determinism and free will that has occupied philosophers for centuries. This point is also stressed by Gazzaniga in The Ethical Brain who notes that notions of rational responsibility are simply absent from neuroscience (p. 101). This is not because neuroscientists have failed to find the neuroscientific correlate of responsibility, it is because the aims, goals, methods and conceptual resources of neuroscience make reference to rational responsibility inappropriate. The fact that the brain is causally implicated in human psychology does not imply that there is, or could be, a neuroscientific account of—or correlate of—rational responsibility. The brain is causally implicated in lots of things—e.g. marriage, buying a car, promising—but this does not mean that it makes sense to talk of there being a neural correlate—or, perhaps, a subatomic correlate!—of marriage (perhaps distributed across two brains?), or of economic transactions and promising.
Let us touch upon another topic in the neuroscience of ethics discussed by Gazzaniga, and by Adina Roskies in the Neuroethics volume: the neuroscience of moral intuition and moral judgement. It has long been known that people's moral intuitions vary with regard to what seem to be identical scenarios in terms of their consequences. For example, most people judge that it would be wrong to push a person onto a railway track to save five others whilst also judging that it would be morally permissible—perhaps even obligatory—to throw a switch that changed the path of a train so that it crashed into one person, rather than five. The consequences in each case are the same (one killed, five saved) but moral intuitions differ. The key variable here is whether or not the scenario is a ‘personal’ or ‘impersonal’ one (i.e. pushing a person onto a track is much more personal than the impersonal throwing of a switch). There is evidence (e.g. see Greene et al., 2001; Casebeer 2003; Greene 2003) that there is a distinctive kind of response to ‘personal’ scenarios that is absent from ‘impersonal’ cases, and that this affective response is subserved by distinctive, localized, patterns of activity in brain regions strongly correlated with emotional arousal. Patients with ventromedial frontal damage, however, exhibit an interesting anomaly. Although they state the same things as ‘normal’ subjects, they do not exhibit the same contrast in emotional arousal between the ‘personal’ and ‘impersonal’ scenarios. Roskies argues that such empirical neuroscientific findings are of great relevance to ethics, in that they allow us to understand the nature of moral judgement. By drawing upon such empirical findings, and by relating it to a wide body of neuroscientific findings about the integration of—and potential dissociation of—emotional and cognitive systems in the brain, she argues that moral judgement is best viewed as involving two distinct components (affective and cognitive) which can, as in the patients with ventromedial frontal damage, come apart. Roskies then argues that such findings show that a conceptual thesis—often called internalism—in ethics is false. The thesis is that certain moral judgements are, just in virtue of their subject matter, intrinsically motivating. If someone judges that morally she ought to do something then she must be, all things being equal, motivated to do that thing (and would do it provided no countervailing considerations take precedence). Patients with ventromedial frontal damage seem to align with normal subjects in terms of their moral judgements but not with regard to their motivation. Now, obviously this is not tested directly (e.g. by getting the patients to push people onto tracks), but, rather, indirectly by neural imaging, by skin conductance response, and so on. This evidence suggests that although these patients say the same things as normal people their motivation does not align with what they say. This shows, Roskies suggests, that internalism is false.
It is not clear how empirical evidence could show this thesis to be true or false given that internalism is not an empirical claim in the first place. It is not as if moral philosophers have looked at people's judgements, and then their motivations, and then concluded that they are linked (any more than they have looked at all the bachelors and all the unmarried men to draw the conclusion that all bachelors are unmarried). We may, of course, contest such a thesis, and argue against it as many philosophers have, but empirical evidence would not do the job. Roskies assumes that the patients' speech acts are the expression of moral judgements, but those who are committed to internalism will agree that there is some deficit in the patient's cognitive competences, but will argue that the deficit is one such that their speech acts do not correspond to their judgements: given the lack of motivation they are not making moral judgements, even if they are saying words that have moral content and are capable of reasoning with them (e.g. by analogy, one can say things that one does not believe and work out the implications of such things without having to believe them).
Where Roskies's use of the neuroscientific evidence is careful and well argued, Gazzaniga draws upon the same kind of neuroscientific evidence used by Roskies to conclude his book with a much wilder line of speculation. The line of speculation concerns the possibility of a neuroscientifically informed ‘universal ethics’. The proposal is sketchy and not at all clear to me, but seems to start with the idea that there is something that is true of all (normal) human agents with regard to their basic cognitive and affective dispositions: we are disposed to respond emotionally in certain ways, to react to social situations in similar ways, and so on. Suppose we do accept this assumption (though, as Gazzaniga notes, many thinkers throughout history have disagreed with it), what follows? And how is this supposed to provide the basis for a universal ethics? For example, some ethical systems—including branches of Judaism, Islam and Christianity—involve distinctive assumptions about the sources of ethical knowledge, placing it in ancient texts or in the prescriptions of those who are acknowledged authorities in interpreting such texts. Other ethical systems do not have this structure at all: the source and authority of ethical claims is to be found elsewhere (in, for example, the power of reason, as Kant argued). How, one might wonder, are neuroethical claims going to establish a universal authority? More generally, I find it hard to see how the claim that human beings have the same kind of cognitive structure lends any support at all to the idea that either there could be, or, more puzzlingly, that there ought to be a ‘universal ethics’. Suppose human beings, as a rule, tend to respond in certain ways to people whom they know, and in a different way to strangers: this fact tells us nothing about how we ought to act towards each.
In conclusion, because there are connections between ethical and legal concepts on the one hand, and folk psychological concepts on the other, neuroscience is likely to be of some relevance to ethical and legal debates where folk psychological notions are in play. But we should be wary, and do our best to distinguish three very different kinds of role that neuroscience might play here. The first is that neuroscientific findings can make a relevant contribution to our folk psychology allowing us to ‘fine tune’ ascriptions of responsibility; or, in the case of the prediction and management of ‘out of control’ behaviour, it may allow us better ways of influencing and adjusting people's psychological dispositions. The second is that ethical, legal and folk psychological concepts can be reduced to neuroscientific ones. This seems extremely problematic, as there is no analogue of rationality, justice, crime or rational responsibility in neuroscience. The third is that neuroscience can replace or eliminate some of our ethical, legal and folk psychological concepts (and their use in certain practices). The underlying idea—and this is one that Churchland has explored elsewhere (e.g. Churchland, 1986)—is that our folk psychological concepts are flawed, or inadequate in certain ways, and that various social practices and institutions (such as the criminal justice system) would be better framed in terms of (some future) neuroscience. These distinctions are worth bearing in mind by anyone exploring, or working within, this new domain of neuroethics and especially within that branch of neuroethics that we have discussed here: the neuroscience of ethics.
Institute for Philosophy and Public Policy Lancaster University United Kingdom
References
Casebeer WD. (2003) Moral cognition and its neural constituents. Nat Rev Neurosci 4:841–7.
Churchland PS. (1986) Neurophilosophy: toward a unified science of the mind-brain. (MIT Press, Cambridge MA).
Goodenough O and Prehn K. (2004) A neuroscientific approach to normative judgment in law and justice Philosophical transactions of the Royal Society of London. Series B. Biol Sci 359:1709–26.
Greene J. (2003) From neural ‘is’ to moral ‘ought’: what are the moral implications of neuroscientific moral psychology? Nat Rev Neurosci 4:847–50.[CrossRef]
Greene JD, Sommerville RB, Nystrom LE, Darley JM, Cohen JD. (2001) An fMRI investigation of emotional engagement in moral judgment. Science 293:2105–8.
Levinsky N. (2001) Ethics and the kidney. (Oxford University Press, Oxford).
Roskies A. (2002) Neuroethics for the new millennium. Neuron 35:21–3.[CrossRef][Web of Science][Medline]
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