Patricia Churchland Reviews Michael Gazzaniga book The Ethical Brain

Envision this scene: Socrates sits in prison, calmly awaiting execution, passing the time in philosophical discussions with students and friends, taking the occasion to inquire into the fundamentals of ethics: Where do moral laws come from? What is the root of moral motivation? What is the relation between power and morality? What is good? What is just?

Ever modest, Socrates confesses ignorance of the answers. The pattern of questioning strongly hints, however, that whatever it is that makes something good or just is rooted in the nature of humans and the society we make, not in the nature of the gods we invent. This does not make moral rules mere conventions, like using a fork or covering one's breasts. There is something about the facts concerning human needs that entails that some laws are better than others.

From the time of Socrates to the present, people have sought to give a natural basis for morals—that is, to understand how a moral statement about what ought to be done can rest on hard facts, albeit facts about conditions for civility and peace in social groups. How can ethical claims be more than mere conventions? How can such claims be rooted in facts about human nature but have the logical force of a command?

Developments in evolutionary biology have helped to explain the appearance of moral motivation in humans and in other eusocial animals—animals that display behavior involving cooperation, sharing, division of labor, reciprocation and deception. In these species, various forms of punishment (shunning, biting, banishing, scolding) are visited on those who threaten the social norms. Ethological studies help us appreciate that, at a basic level, human social behavior has much in common with that of other species...

If you find Gazzaniga's book of interest you'll enjoy Brain Wise by Patricia Churchland it is an excellent introduction to what neuroscience teaches us about common philosophical problems.