Darwin and Natural Law

Issue #13 of DIALOGOS: An Interactive Journay of Science, Philosophy, and Theology


In this issue of Dialogos, we enter into the realm of "sociobiology", a subject greatly popularized in the writings of E.O.Wilson (see Issue #11 of Dialogos) but here discussed with a object of recovering something of the approach to ethical reasoning that has become generally known (and greatly criticized) as the appeal to "natural law".  In the article that follows, which first appeared in Science & Spirit  Magazine, Prof. Arnhart attempts to show how Darwin's own approach to what he considered to be the moral or ethical implications of his thought, which in many ways was similar to that of Aristotle and the later Stoic philosophers, was largely cast aside by his followers who were under the spell of Hobbesian and Kantian currents of thought.

While Arnhart's article is written primarily from a historical perspective, we hope that our readers will not hesitate to share their insights as to what this approach might imply in various issues presently facing us -- for example, those raised in Issue #10 regarding the future of sexuality. (R.W. Kropf, ed.)

The Search for a Darwinian Science of Ethics

By Larry Arnhart

The sciences of inanimate nature -- such as physics and chemistry - - would seem to contribute little directly to our understanding of ethics. The life sciences, however, might have more to offer. After all, biology includes the study of human conduct as animal behavior. Indeed, Charles Darwin, in his book on human biology, The Descent of Man, argued for a biological theory of ethics as manifesting what Darwin called "the moral sense."

The question of whether there can be a Darwinian ethics is controversial. In the Darwinian tradition of biology, there have been at least two opposing positions. One group I would identify as the Aristotelian Darwinians, and the other as the Hobbesian Darwinians. The Aristotelian Darwinians agree with Aristotle in believing that human beings are, by nature, social animals, and therefore ethics is ultimately rooted in the natural desires of human beings as social animals. The Hobbesian Darwinians, by contrast, agree with Thomas Hobbes in believing that human beings are naturally asocial animals, and therefore ethics arises as a cultural artifice necessary for conquering the naturally selfish desires of human beings.

I believe the Aristotelian Darwinians are closer to the truth. They are also closer to Darwin himself.

The Moral Debate About Darwinism

In 1836, Charles Darwin was 27 years old and had just returned to England after his long voyage around the world on HMS Beagle. He began to record his ideas about natural history in a series of note- books. These note-books, which were intended only for his own private use, show the character of his mind at work more clearly than any of his writing that was written for publication. We see him struggling to formulate for the first time his idea of natural selection. We also see that his intense interest in the moral implications of his biological ideas led him to read widely in ethical philosophy.

Darwin was particularly influenced by his reading of James Mackintosh's Dissertation on the Progress of Ethical Philosophy, which had just been published in 1836. According to Mackintosh, all of the fundamental controversies in modern ethical philosophy were initiated by Thomas Hobbes (1588-1679) in his book Leviathon (1651). While Aristotle (384-322 B.C.E.) had claimed that human beings are by nature social and political animals, Hobbes had argued against Aristotle that human beings are by nature asocial and amoral beings. Mackintosh criticized Hobbes and insisted that human beings are endowed by nature with a moral sense that approves certain actions without regard to their consequences, although the essential tendency of such actions is to promote the common advantage or general happiness.

When Darwin developed his biological theory of human sociality and morality, first sketched in his notebooks and then published later in The Descent of Man, he was decisively influenced by Mackintosh's reasoning. He went beyond Mackintosh, however, in showing how the moral sense could have arisen in human nature as a product of natural selection. Darwin's general claim was that any social animal with natural capacities for speech and reasoning comparable to those of human beings would develop a moral sense. This has led one Darwinian scholar (Robert Richards) to conclude: "Aristotle believed that men were by nature moral creatures. Darwin demonstrated it."

Darwin's ethical naturalism revived an Aristotelian tradition that Hobbes had challenged in his denial that human beings were by nature political animals. Against Aristotle, Hobbes had insisted that morality and politics could not be rooted in the animal nature of human beings because of the radical gulf between animal instinct and human learning. Despite the monism of Hobbes's materialism, his moral and political teaching presupposes a dualistic opposition between animal nature and human will: in creating political order, human beings must transcend and conquer their nature. This Hobbesian dualism was elaborated by Immanuel Kant (1724-1804) in formulating the modern concept of culture. Culture is that uniquely human realm of artifice in which human beings escape their natural animality to express their rational humanity as the only beings who have a "supersensible faculty" for moral freedom. Through culture, human beings free themselves from the laws of nature. This Hobbesian and Kantian concept of culture supports the common view today that the ideas and methods of the natural sciences can never explain human conduct, because human beings transcend nature through cultural learning.

Darwin's argument for the continuity between human beings and other animals denies the concept of culture by denying the dichotomies on which it rests: biology versus culture, nature versus nurture, instinct versus learning, animality versus humanity, facts versus values. As soon as Darwin published his naturalistic theory of morality in The Descent of Man in 1871, he was attacked by some religious thinkers, who insisted on a Kantian separation between nature and morality. Although the human body could be explained as a natural product of biological evolution, in this view, the human soul was a supernatural product of divine creation. As an expression of the soul's transcendence of nature, human morality manifested a uniquely human freedom from natural causality.

Biologist Thomas Huxley (1825-1895) defended Darwin against this attack when The Descent of Man was first published. But later in his life, particularly in his famous lecture on "Evolution and Ethics," Huxley tended toward a dualistic theory of ethics. Huxley adopted the Hobbesian-Kantian view that since human beings in their natural state were selfish and asocial, the moral improvement of humanity required a self-abnegating denial of human nature. Because of the "moral indifference of nature," Huxley claimed, one could never derive moral values from natural facts. Interpreting Darwin's "struggle for existence" as a Hobbesian war of all against all, so that there was no natural ground for social cooperation or moral concern, Huxley concluded that "the thief and the murderer follow nature just as much as the philanthropist." Social progress could arise, therefore, only from a checking of the "cosmic process" by the "ethical process," and thus building "an artificial world within the cosmos." This understanding of ethics as an "artificial world" built up through a human conquest of nature showed the influence of the Kantian concept of culture.

Thus did Huxley become, in his later years, the founder of what I have identified as the Hobbesian tradition of Darwinism. Like Huxley, the Hobbesian Darwinians assume that the biological nature of human beings inclines them to selfishness and violence, and therefore ethics requires a human conquest of nature through culture. Recently, two of the most influential exponents of this position have been biologists Richard Dawkins and George Williams. Williams, for example, hopes that ethics as a cultural invention can provide "the humane artifice that can save humanity from human nature." Like Huxley, Williams insists that ethics cannot be rooted in human nature because of the unbridgeable gulf between the selfishness of our natural inclinations and the selflessness of our moral duties.

Reviving Aristotelian Ethics

Aristotelian Darwinians deny this claim that morality must be a cultural construction with no roots in biological nature. Adhering to Darwin's original position, these new Aristotelians argue for investigating the natural history of value and morality, in which the good would be understood as the satisfaction of anima] desires. To some extent, this satisfaction of natural desires is controlled by rigid instincts; but many animals, to varying degrees, satisfy their desires through social learning and flexible behavior. In the complexity of their learning and behavior, human beings differ in degree but not in kind from other animals. Human beings are surely unique in being able to deliberately shape their moral habits and beliefs to conform to some general conception of a good life well lived. But even this capacity for deliberation can be understood as an elaboration of cognitive capacities shared with other animals that have complex nervous systems.

Against the assertion that human beings are naturally amoral or immoral, contemporary zoologist Frans de Waal has argued that morality is rooted in our primate ancestry. The view of human beings as innately depraved is not supported by the biological evidence, but rather reflects a Calvinist doctrine of original sin. De Waal explains: Evolution has produced the requisites for morality: a tendency to develop social norms and enforce them, the capacities of empathy and sympathy, mutual aid and a sense of fairness, the mechanisms of conflict resolution, and so on. Evolution has also produced the unalterable needs and desires of our species: the need of the young for care, a desire for high status, the need to belong to a group, and so forth.

the biological understanding of ethics as rooted in human nature is Aristotelian because it belongs to the tradition of ethical naturalism that began with Aristotle. For Aristotle, the aim of ethics and politics is to shape moral character to satisfy the natural desires of human beings. In the Nicomachean Ethics, he studies the ethical and intellectual virtues necessary for human happiness. In the Politics, he shows how the social and governmental structures of various political regimes can foster or impede the virtues of human character. Judging human virtues and political regimes cannot be determined by universal rules, he insists, because the diversity in the individual and social circumstances of life requires prudence or practical wisdom, which cannot be reduced to abstract rules. Nevertheless, human nature does provide a universal standard of judgment: human beings are by nature social and political animals who use their natural capacity for reasoning to deliberate about the conditions of their social and political life. Therefore, we can judge political communities by how well they conform to the nature of human beings as political animals and rational animals. We thus appeal to what Aristotle called "natural right."

Aristotle was a biologist, and his view of human beings as political and rational animals manifests his biological understanding of human nature. His ethical writings incorporate ideas drawn from his of biological writings. In the Nicomachean Ethics, Aristotle compares human beings with other social animals, particularly in explaining the biological basis for parent-child bonding and other forms of affiliation or friendship (philia). In the Politics, he explains the political nature of human beings by comparing them with other political animals such as the social insects.

Some of the scholars studying Aristotle have come to recognize the importance of Aristotle's biology for all of his philosophic writing. Some of this new scholarship now suggests that for Aristotle, as Stephen Salkever has said, "ethics and politics are in a way biological sciences." And at the same time, some biologists have shown new respect for Aristotle's contributions to the history of biology. "All of biology," biologist John Moore has declared, "is a footnote to Aristotle."

Aristotle's idea of natural right as rooted in biology is fundamentally compatible with Darwin's account of human nature. Like Aristotle, Darwin claimed that human beings are by nature social animals -- coming together first in families and then in larger social groups. He also agreed with Aristotle in deriving morality from human nature. From David Hume Darwin adopted the idea that morality was founded on a natural moral sense, and he explained this moral sense as a natural adaptation of human beings shaped by their evolutionary history. In contrast to Kant's dualistic separation between morality and nature, Hume's idea of the moral sense as rooted in natural human desires is close to Aristotle's position.

I would argue for a conception of "Darwinian natural right" as including Aristotle's idea of natural right, Hume's idea of the natural moral sense, and Darwin's idea of the moral sense as shaped by natural selection. In a new book, I defend ten propositions that state this new Aristotelian view of Darwinian evolution and human ethics.

( 1 ) The good is the desirable, because all animals capable of voluntary movement pursue the satisfaction of their desires as guided by their information about the world.

(2) Only human beings, however, can pursue happiness as a deliberate conception of the fullest satisfaction of their desires over a whole life, because only they have the cognitive capacities for reason and language that allow them to formulate a plan of life, so that they can judge present actions in the light of past experience and future expectations.

(3) Human beings are by nature social and political animals, because the species-specific behavioral repertoire of Homo sapiens includes inborn desires and cognitive capacities that are fulfilled in social and political life.

(4) The fulfillment of these natural potentials requires social learning and moral habituation. Although the specific content of this learning and habituation will vary according to the social and physical circumstances of each human group, the natural repertoire of desires and cognitive capacities will structure this variability.

(5) We can judge divergent ways of life by how well they nurture the natural desires and cognitive capacities of human beings in different circumstances, but deciding what should be done in particular cases requires prudent judgments that respect the social practices of the group.

(6) Rather than identifying morality with altruistic selflessness, we should see that human beings are moved by self-love, and as social animals they are moved to love others with whom they are bonded as extensions of themselves.

(7) Two of the primary forms of human sociality are the familial bond between parents and children and the conjugal bond between husband and wife.

(8) Human beings have a natural moral sense that emerges as a joint product of moral emotions such as sympathy, guilt, and indignation, and moral principles such as kinship, mutuality, and reciprocity.

(9) Modern Darwinian biology supports this understanding of the ethical and social nature of human beings by showing how it could have arisen by natural selection through evolutionary history.

(14) Consequently, a Darwinian understanding of human nature supports a modern version of Aristotelian natural right.

Nature and Nature's God

Some religious believers might worry that this Darwinian view of ethics ignores the importance of religion. On the contrary, Darwinian natural right confirms the ethical teaching of religion, at least so far as religious ethics is rooted in human nature.

I agree with Sir John Templeton that science and religion ultimately converge, because the ethical "laws of life" taught by religion can be confirmed by modern natural science. He established The John Templeton Foundation to promote research in the natural sciences for the study of those ethical laws. And it would seem that the clearest scientific support for Templeton's "laws of life" would be found in a Darwinian view of ethics.

The observational and logical methods of science are founded on our natural human experience of the world. Therefore, the common ground on which science and religion can meet is the natural study of natural law by natural reason. The only kind of religion that can be studied by natural science is natural religion.

Templeton believes that the scientific probing of the mysteries of nature should cause us "to pause humbly before the majesty and infinity of what Jefferson called "nature and nature's God." The God who legislated the "laws of life" as laws of nature is the God of nature. And thus the religion that would support belief in and obedience to those laws is a natural religion. Those religious conceptions that are rooted in natural human experience can reinforce the natural moral inclinations of human beings. If there is to be an "experimental theology," as Templeton proposes, it must be a natural theology of human nature as studied by natural science. And the most promising area of science for that purpose is the Darwinian biology of human nature.

When Templeton argues that there are universal "laws of life" that determine human happiness -- laws that are confirmed by religious teaching, scientific study, and ordinary experience of the world -- he takes a position similar to that of Thomas Aquinas ( 1225-1274) in his teaching about natural law. Aquinas looked for the common ground between Christian theology and Aristotelian philosophy. As part of that project, he concluded that there is a natural moral law conforming to the natural inclinations or desires of human beings in their striving for happiness. And although this natural law is ultimately a product of God's creative activity, this natural law can be known by natural reason even without religious belief. As distinguished from natural law, divine law depends on belief in God's revelation through the Bible. While natural law suffices for the earthly happiness of human beings, divine law is necessary for their eternal happiness in Heaven. Earthly happiness requires only a natural knowledge of the natural conditions of life on earth, which comes from natural law. Eternal happiness requires a supernatural knowledge of the supernatural conditions for eternal salvation, which comes from divine law. Aquinas's natural law can be understood as a law of human biology. Aquinas sometimes explains natural law in the light of Aristotle's biology. And Aquinas likes to quote the remark of Ulpian, a Roman jurist, that "natural right is that which nature has taught all animals."

Insofar as the moral sense is rooted in human nature, it can be understood by reflection on the lessons of natural human experience without any need for religious doctrine. That is what Aquinas means when he separates natural law and divine law. By natural law, human beings need the moral and intellectual virtues to satisfy their natural desires as they strive for earthly happiness. The need for these virtues becomes evident to anyone who thinks clearly about the conditions of human life on earth. This natural understanding of morality does not require religious belief. Nevertheless, belief in divine law can reinforce this natural morality by strengthening the religious believer's devotion to the natural virtues. The ultimate purpose of divine law, however, is not to strengthen the natural virtues but to instill the supernatural virtues, because the aim of divine law is not the temporal happiness of human beings as mortal creatures adapted for life on earth, but the eternal happiness of human beings as spiritual creatures who long for union with their Creator.

If we really do yearn to transcend the limits of our natural mortality and attain a perfect happiness beyond death, the pursuit of that happiness must be by faith in revealed religion. But however that may be, we can rest assured that our earthly happiness is securely founded in our nature as mortal animals endowed with a moral sense that serves our natural desires.

Larry Arnhart is a political scientist at Northern Illinois University. He is the author of books on Aristotle and the history of political philosophy. His latest book is Darwinian Natural Right: The Biological Ethics of Human Nature (State University of New York Press, 1998). His mailing address is 1015 Ashley Drive, DeKalb, IL 60115, USA.

See also the exchange between Arnhart and Michael J. Behe and William A. Dembski in "Conservatives, Darwin & Design: An Exchange" in First Things: A Monthly Journal of Religion and Public Life, Number 107 (November 2000, pp. 23-31)

For another insight into the understanding of "natural law" as well as the consequences of it's being discarded, see the linked file " The Implications of George Grant's Rejection of Natural Law" by Kenneth Russell.

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