Murphy, Nancey. “Supervenience and the Nonreducibility of Ethics to Biology."

Nancey Murphy considers the role of supervenience in the relation of evolutionary biology and ethics. She argues that God acts in the moral as well as the biological sphere. She also challenges the attempt to reduce morality to biology and she affirms the claim that objective moral knowledge is dependent on a theological framework.

According to Murphy, the contemporary atomist-reductionist program can be traced to the rise of modern science with the transition from the Aristotelian hylomorphism to Galilean atomism. Following the success of Newtonian mechanics, atomism was extended to chemistry. In the nineteenth century, attempts were made to extend atomism to biology and, in our century, to the human sphere, including psychology and a general epistemological theory of the relations between the sciences. In this view, the world is seen as a hierarchy of levels of complexity with a corresponding hierarchy of sciences. Causation is strictly bottom-up from the lowest level to the top of the hierarchy. Murphy draws on Francisco Ayala’s classification and lists six types of reductionism, including methodological reductionism which, by its success, lends credence to the other five. Bottom-up causality and the claim that the parts take priority over the whole embody what is, in fact, a metaphysical assumption. Modern thought also extended atomism to areas such as political philosophy and ethics through the writings of Thomas Hobbes and Immanuel Kant. Still, the determinism of the laws of physics has raised problems for human behavior. Materialists like Hobbes have simply accepted determinism, while dualists such as Descartes have sought to avoid it, but in its place have raised the mind-body problem, and the resulting separation of the natural and social sciences a century later.

Murphy concludes that a proper understanding of ethics and biology will require a thorough response to reductionism. The key will be nonreductive physicalism, originating in the work of Roy Wood Sellars, and now including the focus on emergent properties of hierarchical systems. Sellars, in emphasizing the significance of organizations and wholes, opposes Cartesian dualism, absolute idealism, and reductive materialism. Murphy then cites scientific evidence for nonreducibility: interactions with the environment portray an entity as part of a larger system and entail both top-down and whole-part analyses which complement the bottom-up approach and lead to language about emergence. The irreducibility of concepts entails the irreducibility of laws. But how are we to explain these problems with reducibility if our analysis, though multi-layered, still refers to one reality?

Here Murphy introduces the concept of supervenience in order to give a non-reducible account of morality and mental events. R. M. Hare introduced the term in 1952, and Donald Davidson developed it in 1970. It is now widely used in philosophy, though not without disagreement. Murphy’s emphasis is on circumstance: identical behavior in different circumstances could constitute different moral judgments, and such supervenient properties are not necessarily reducible. Then she returns to the hierarchical model of the sciences with a branching between the human and physical sciences she and George Ellis suggested. The human sciences are incomplete without ethics. In this scheme, the moral supervenes on the biological if biological properties constitute moral properties under the appropriate circumstances. She draws on Alasdair MacIntyre and on Philip Kitcher’s critique of E. O. Wilson to argue that claims to reduce ethics to biology are due to meta-ethical ignorance, challenging Richard Alexander and Michael Ruse in passing. Instead Murphy places ethics between the social sciences and theology. The former, rather than being value-free, now involves moral presuppositions and ethical questions. Ethics traditionally drew upon a concept of humankind’s ultimate telos. The Enlightenment severed the ties to this tradition but kept the same moral prescriptions. Modern philosophers, failing to find an objective basis for moral discourse, reduced moral claims to empirical observations. All of this is due to our forgetting that the “ought” is only half of a moral truth; it is actually connected to a telos and a specific “is” statement. Murphy next discusses the supervenience relations that obtain as we move up the scale. The predicate of virtue supervenes on psychological characteristics, but only if there are nonreducible circumstances related to the ultimate goals of human existence.

Murphy concludes with the relation between ethics and biology. Here we extend the subvenience of virtues downward in the hierarchy. According to MacIntyre, virtues are acquired and not genetically determined traits. Still ethics will have much to learn from biology. Finally, all moral systems are dependent for their justification on beliefs about reality. Murphy dismisses claims like that of Jacques Monod regarding the meaningless and purposelessness in nature. Instead, we must reject reductionism by emphasizing the top-down connections from theology to ethics as well as the general inadequacies of reductionism.

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