<<

COMMENT BOOKS &

NEUROETHICS The origins of morality Our values may have biological roots, finds Adina Roskies, but we still need .

orality isn’t just what your father, levels of oxytocin and evolutionary approach. She is less charitable priest or favourite philosopher vasopressin. to some other moral philosophers, such as told you. It is a natural phenom- Despite her natural- , who grounded morality in Menon, the result of a complex, evolved and ism, Churchland does the operation of reason. Although Church- learned of capacities. Philosopher of not shy away from land’s argument that morality has biological neuroscience argues criticizing naturalistic roots demonstrates that our moral behaviour in Braintrust that moral behaviour views that she deems is not grounded in reason alone, her quick emerges from the mechanisms that evolved to be based on inad- dismissal of a central role for deliberation in to promote social interactions. equate evidence. She moral cognition potentially deprives us of Churchland hypothesizes that is “a argues that it is mis- valuable insights about the nature of human four-dimensional scheme for social behav- leading to conceive Braintrust: What morality. For example, it may be the ability iour that is shaped by interlocking brain of morality as innate, Neuroscience Tells to step back from our biological inclinations Us About Morality processes”. She identifies these dimensions genetically specified PATRICIA S. and deliberate abstractly that defines human as: caring, rooted in a biological attachment or associated with one CHURCHLAND prosocial behaviour as uniquely moral. to kin and kith; the ability to recognize oth- module in the brain. Princeton Univ. Press: So how do we ascertain which of the com- ers’ psychological states; problem-solving in Although many social 2011. 288 pp. $24.95 peting biological drives, urges and intuitions a social context; and social learning. Different traits are genetically should govern our behaviour? This brings brain networks contribute to each. And even influenced, few can be linked to single genes. us to the descriptive– distinction, simple moral decisions, such as whether to Instead, moral behaviour emerges as a solu- the famously unbridgeable gulf between steal another’s possession, involve at least a tion to complex social problems. “is” and “ought”. Churchland tries to argue few of these dimensions. She argues effectively against the popular that this gulf is more apparent than real. But Churchland describes the biological view that share a “moral grammar” in my view, she goes too far in denying the mechanisms that serve these functions in an or a universal set of moral intuitions, but legitimacy of this question. I am sympathetic accessible way, and makes a case that they are less convincingly against the position that to her position that knowing how things are fundamental to our moral practices. Although human morality is built on a set of shared, (facts) can influence deliberation about what there is no clear argument that these dimen- emotion-involving sensitivities that become should be done (values). However, it is still sions are distinct, articulated differently in different open to us to question what values are the best interlocking or suf- “It is still open and environments. Churchland offers pen- to espouse, or whether human flourishing is ficient to account for to us to question etrating criticisms of arguments for the role the only to which we ought to aim. all aspects of ethical what values of mirror neurons in and This perplexing question of moral author- , she suc- are the best to . These neurons respond when a ity seems obvious to people of faith. In the ceeds in painting a espouse.” monkey performs a certain goal-directed final chapter, Churchland faces head-on the picture of human action, or sees that action being performed. challenge from . She does an excel- morality as emerging from the social interac- Although mirror neurons are intriguing, they lent job of pointing out the inconsistencies tions of intelligent animals primed for coop- have been invoked to explain a wide vari- and dangers in taking religious authority as erative, context-sensitive behaviour. ety of aspects of social neuroscience, often grounds for moral authority. But where that The tour begins with the biology of “the without adequate empirical or logical justi- leaves us remains unclear. Are we realists, most elemental” values: the neural hardware fication. Churchland’s discussion puts these relativists or nihilists? Churchland’s biology- that grounds self-caring and well-being. areas of research prone to over-interpretation centred picture leaves open significant ques- Churchland’s plausible claim is that our abil- into much-needed perspective. tions about the good and the right that will ity to at all is rooted in the basic neural Churchland demonstrates that there is sub- require philosophical, not biological, answers. mechanisms that evolved to maintain human stantial evidence that biology promotes social In my view, by illuminating the biological viability and reproductive success. These behaviour. But is all such behaviour necessar- foundations on which caring, include neural pathways mediating negative ily good? Any behaviour, even free-riding, and social understanding are based, and and positive reinforcement learning, which cheating and harming, must be supported by by arguing against simplistic views about underlie the experiences of pleasure, and biology. How should we decide what is right? innateness and divine ordination, Church- fear; and hormones such as oxytocin and vaso­ Many philosophers appeal to moral rules to land has delineated the conceptual space still pressin, which figure in social interactions, address this question; Churchland sees no to be navigated concerning which actions are pair bonding and care for offspring. need, and criticizes those moral systems that morally right, how we come to those deci- Thus, Churchland argues, human morality take rules as foundational. sions, and how we justify them. Braintrust is formed on a neurobiological scaffold that Churchland has Aristotelian sensibilities. covers what science tells us about morality. evolved long ago, originally to promote care The Aristotelian idea that morality depends But that is only one side of the story. ■ of self and offspring, and was later co-opted to on the inculcation foster more sophisticated cooperative interac- NATURE.COM of good behavioural Adina L. Roskies is an associate professor in tions. She notes fascinating data that suggest More on the habits that promote the Department of Philosophy, Dartmouth that high-level social phenomena such as , psychology of morals: human flourishing fits College, New Hampshire 03755, USA. generosity and punishment are influenced by go.nature.com/alxpfa well with the author’s e-mail: [email protected]

166 | NATURE | VOL 472 | 14 APRIL 2011 © 2011 Macmillan Publishers Limited. All reserved