Why Science Can’t Tell Us How to Live

Can science tell us how we ought to behave? In Science and the Good, a book that crosses the boundaries of history, philosophy, and psychology, sociologist James Davison Hunter and philosopher Paul Nedelisky examine nearly 400 years of scientific attempts to discover the sources and meaning of morality. That effort, they conclude, has failed. Science can tell us the way things are but not the way things ought to be. In the language of philosophy, it can’t derive an “ought” from an “is.”

Hunter and Nedelisky define the scientific quest for morality as an attempt to use empirical methods to discover universal principles for ethical action. The scientists and ethicists engaged in it operate from the assumption that everything about life on earth can be explained by natural processes alone.

Before the dawn of the Enlightenment era, late-medieval scholastics such as Thomas Aquinas had produced moral theories based on theological, rather than naturalistic, premises. They believed that through observation of the created order, one could discover the purposes for which God had designed particular creatures or activities—and the moral laws that flowed from those purposes. But in the 17th century, the Dutchman Hugo Grotius and other political philosophers wanted to discover a moral code that could operate without invoking God.

With Christendom split into competing factions that were slaughtering each other over sectarian disagreements, Grotius and like-minded intellectuals doubted whether religion could create a universal moral consensus. Could science succeed where religion had failed? Instead of speculating about divine purposes for creation, Grotius thought, moral theorists should ask one question: What actions contribute to social harmony? John Locke further refined this idea by suggesting that “good” is what brings pleasure, while “evil” is what produces pain.

A Fatal Philosophical Error

The proponents of this new approach shared two assumptions that would guide scientific investigations of morality for the next three centuries and beyond. First, they agreed that the moral law was not divinely ordained but something human beings created (and collectively agreed to follow) because of its practical benefits. And second, they believed that moral laws existed solely for the sake of human happiness. Actions were moral if they made society happier.

In the early 19th century, Jeremy Bentham and John Stuart Mill made this assumption the backbone of their new philosophy of utilitarianism. To determine what was right, they argued, one must measure the total societal happiness produced by each possible human action—and then pursue actions that produce “the greatest good for the greatest number.” By the late 19th century, some Social Darwinists were arguing that evolution itself guaranteed the “greatest good for the greatest number.” As the human race “evolved,” they believed, it was becoming progressively more moral.

But in the early 20th century, most intellectuals abandoned the quest for a scientific account of morality, because they realized that the quest had been based on a fatal philosophical error. The utilitarians had equated morality with happiness, and the evolutionists had equated it with social progress. But neither of these theories could offer any scientific proof. What if morality meant something else entirely? And if there were good reason to question whether variables like individual happiness or social well-being were identical to morality, then perhaps morality might not be open to scientific inquiry after all.

The late 20th century, however, saw the quest reopened. By this point, advances in neuroscience, psychology, and evolutionary theory had encouraged some scientists to hope that they might find the answers that had eluded an earlier generation of political philosophers. Unlike Grotius or Bentham, most of the new moral scientists—experts like Harvard psychology professor Joshua Greene or Patricia Churchland, a philosopher of neuroscience—were less interested in finding a scientific basis for morality than in explaining how moral thinking worked. Subscribing to an updated version of David Hume’s idea that moral thought was nothing but emotion (and convinced that evolutionary history could explain the origins of moral thinking), the new moral scientists analyzed the human brain to uncover the cognitive processes behind moral reasoning and then sought an evolutionary account of their origins.

Did the new moral scientists of the late 20th and early 21st centuries believe in an objective morality? Some, such as Duke philosophy professor Alex Rosenberg, did not, but most (including Churchland) still assumed that utilitarianism could provide a universal moral ethic. Evolution, the latter group argued, had produced a system of moral reasoning that helped society function on a practical level, even if it wasn’t based on anything transcendent. Unlike the evolutionists of the late 19th century, they did not believe that evolution was destined to make society morally better. They did believe, however, that evolution had helped propagate moral sentiments that were ideally suited to relatively stable and flourishing societies. These new moral scientists argued, for example, that evolution had produced altruism, because social groups whose members were willing to sacrifice individual interests for the sake of the community stood a greater chance of surviving.

Hunter and Nedelisky are suspicious of this claim. Noting that its proponents generally arrive at exactly the same moral code they espoused before their study—that is, contemporary secular Western morality, with its pluralistic ethic and its commitment to rights-conscious tolerance—they question the objectivity of the new moral science. But more importantly, they suggest that this project runs into the same objection that doomed its 19th-century forebears: namely, that moral scientists are not really studying morality, but something else—whether human happiness or social well-being—that they have mistakenly labeled morality.

A genuine moral philosophy, Hunter and Nedelisky argue, would not be merely pragmatic. It would go beyond arguing that people should behave in a certain way for the sake of some higher good, like social harmony. It would include a commitment to intrinsic human rights, and a discussion of virtues and character traits that should be pursued as ends in themselves, not merely as pathways to happiness.

The Humanities Won’t Save Us

At the end of their book, Hunter and Nedelisky ask: If science cannot provide a universal standard of moral truth, how can we arrive at one? The authors’ answer is likely to disappoint many Christian readers, because it falls short of affirming the necessity of a God-centered framework. Hunter and Nedelisky argue that reasoned dialogue that acknowledges deep cultural differences—as well as shared values—is the only way forward.

One of the central problems of the quest to understand morality scientifically, they suggest, is that the scientists and philosophers engaged in the enterprise assumed that moral laws were, like physical laws, universally accessible—and that they would be universally accepted as soon as they were discovered. But perhaps, Hunter and Nedelisky suggest, humans cannot agree on moral norms because they do not share the same cultural presuppositions.

Thus, if we are to arrive at a common understanding of morality, we must first acknowledge the distance between our varying cultural assumptions and then attempt to understand our competing moral claims through dialogue. Hunter and Nedelisky conclude by recommending “history, literature, poetry, philosophy, sociology, and the world’s great religious traditions” as possible guides to achieving “a more just, inclusive, and humane world.”

How should Christians react to this conclusion? Hunter and Nedelisky may have had good reasons for leaving Christian moral theology aside in a book focused primarily on secular science. They certainly offer valuable insights about the weaknesses of contemporary utilitarian or scientific analysis, and those insights can help rebut the most common assumptions of the “new atheists.”

But in the end, any account of moral reasoning that omits a Christian understanding of right and wrong is destined to fail. For Christians, the fundamental problem with the quest for a scientific understanding of morality is the attempt to establish moral law while explicitly ruling out the possibility of a moral lawgiver. Unless those seeking a common morality through the humanities are open to the idea of grounding that morality in something higher than human beings themselves, they will founder on the same shoals that wrecked attempts to arrive at morality through science. Even the very best history, literature, and philosophy won’t build a reliable bridge between “is” and “ought.”

Selflessness and Sacrifice

No scientific or non-theistic account of morality has answered the question of why human beings have intrinsic dignity. Indeed, some of them have explicitly rejected this idea. As modern horrors like eugenics and ethnic cleansing show all too clearly, it is a short distance from calculating the utility of human actions to calculating the utility of people. The doctrine of imago Dei provides a safeguard for human rights that no version of scientific morality can match.

The greatest danger, though, is not that scientific morality will usher in a “brave new world” of government-approved killing but rather that it will offer privileged people an excuse to justify their own complacency. The intellectuals who pursued a scientific morality have not experienced personal moral transformation from their insights. They have merely invoked science to justify conventional Western liberal ideas that were already part of their cultural milieu.

Scientific morality has not produced the selflessness of a Mother Teresa or the “unearned suffering” of a Martin Luther King Jr. Nor has it inspired the quotidian sacrifices of countless foster parents or those caring for elderly people suffering from Alzheimer’s. Perhaps that is because a Christian moral ethic does not make sense by utilitarian lights. Or perhaps it is because the scientific studies of morality overlook important non-empirical truths, such as human dignity, the eternal value of a human soul, and the transforming power of an incalculable divine grace. Adding God to the equation changes everything.

Daniel K. Williams is a professor of history at the University of West Georgia and the author of Defenders of the Unborn: The Pro-Life Movement before Roe v. Wade (Oxford University Press).

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