In my 1999 book How We Believe I outlined a three-tiered taxonomy of the relationship of science and religion: (1) the Conflicting-Worlds Model holds that science and religion are in a struggle to determine the truth, in which one is right and the other wrong; (2) the Same-Worlds Model contends that science and religion are two equally valid ways of examining reality; and (3) the Separate-Worlds Model argues that each tradition inhabits different domains of knowledge—facts and values—and rarely the twain shall meet. For years I held and defended the Separate-Worlds Model while acknowledging that there are some areas of conflicts; if you believe that the earth is 6,000 years old, for example, your belief is in direct conflict with the geologically dated age of 4.6 billion years.
More and more, however, I see science and religion in conflict, not only in such factual questions about nature (growing by the year as the sphere of science expands into the ether of religious tenets), but in moral matters as well. In my next book, The Moral Arc: How Science and Reason Lead Humanity Toward Truth, Justice, and Freedom, I argue that morals and values can be established and defended through science and reason. Inspired by Galileo and Newton, Enlightenment thinkers consciously applied the methods of science to solve social, political, economic, and moral problems. The experimental methods and analytical reasoning of science created the modern world of liberal democracies, civil rights and civil liberties, equal justice under the law, free minds and free markets, and prosperity the likes of which no human society in history has ever enjoyed. I claim that we owe this salubrious state of affairs primarily to science and reason—and most emphatically not to religion—and thus I am inclined to join the Classical Liberal position in Kevin Vallier’s instructive four-tiered taxonomy (Libertarian, Religious Conservative, Secular Progressive, and Classical Liberal), albeit for reasons that differ from his.
Democracies, for example, have systematically replaced autocracies because democracies empower individuals with a methodology to solve problems instead of an ideology to obey. Democratic elections are analogous to scientific experiments: every couple of years you carefully alter the variables with an election and observe the results. If you want different results, change the variables. The political system in the United States is often called the “American experiment,” and the founders referred to it as such, and thought of this experiment in democracy as a means to an end, not an end in itself.
Many of the Founding Fathers were, in fact, scientists who deliberately adapted the method of data gathering, hypothesis testing, and theory formation to nation building. Their understanding of the provisional nature of findings led them to develop a social system in which doubt and dispute were the centerpieces of a functional polity. Jefferson, Franklin, Paine, and the others thought of social governance as a problem to be solved rather than as power to be grabbed. They thought of democracy in the same way that they thought of science—as a method, not a belief. They argued, in essence, that no one knows how to govern a nation, so we have to set up a system that allows for experimentation. Try this. Try that. Check the results. Repeat. That is the very heart of science. As Thomas Jefferson wrote in 1804: “No experiment can be more interesting than that we are now trying, and which we trust will end in establishing the fact, that man may be governed by reason and truth.”
Even the fundamental principles underlying the Declaration of Independence, which is usually thought of as a statement of political philosophy, were in fact grounded in the type of scientific reasoning that Jefferson and Franklin employed in all the other sciences in which they worked. Consider the foundational line, “We hold these truths to be self-evident, that all men are created equal….” In his biography of Benjamin Franklin, Walter Isaacson recounts the story of how Franklin redacted Jefferson’s phrase, “We hold these truths to be sacred and undeniable” and changed them to “We hold these truths to be self-evident”:
The idea of “self-evident” truths was one that drew less on John Locke, who was Jefferson’s favored philosopher, than on the scientific determinism espoused by Isaac Newton and on the analytic empiricism of Franklin’s close friend David Hume. In what became known as “Hume’s fork,” the great Scottish philosopher, along with Leibniz and others, had developed a theory that distinguished between synthetic truths that describe matters of fact (such as “London is bigger than Philadelphia”) and analytic truths that are self-evident by virtue of reason and definition (“The angles of a triangle equal 180 degrees”; “All bachelors are unmarried.”) By using the word “sacred,” Jefferson had asserted, intentionally or not, that the principle in question—the equality of men and their endowment by their creator with inalienable rights—was an assertion of religion. Franklin’s edit turned it instead into an assertion of rationality.
Assertions of religion in the political sphere are becoming as obsolete as those in the scientific realm, and often just as wrong when they collide with reality. Still, just as in science, people must be free to be wrong, for how else will we come to understand what is right? The private religious beliefs of individuals may be asserted and tested in the public sphere—by which I mean the public marketplace of ideas—but never squelched or forced upon anyone through the law.
Following Kevin Vallier’s example, consider homosexuality and same-sex marriage as an example of how science and reason can determine values and morals. Descriptively, science tells us that human beings have an evolved, innate drive to survive and to flourish, and that one of the most necessary and primal requirements among the many preconditions for life, health, and happiness for most people is a loving bond with another human being. Prescriptively, we can say that granting only a select group of privileged people the right to fulfill this evolved need—while simultaneously depriving others of the same basic right—is immoral because it robs them of the opportunity to fulfill their essence as evolved sentient beings. This is true even if the case were made that such discriminatory practices are better for the group (in a type of utilitarian calculus where the sacrifice of the few is justified if it leads to the greater happiness for the greater number). It is still wrong because the individual is the moral agent, not the group. It is the individual who feels the sharp pain of discrimination, the sting of being excluded, and the insult of being treated differently under the law. Science tells us why they feel this way and reason instructs us what to do about it if we want to continue the moral progress of the Rights Revolutions.
Jonathan Rauch, a long-time advocate for free speech and civil liberties, has documented how winning in the marketplace of ideas is what has accelerated the gay rights revolution more than anything else. Rauch recalls the comment of a caller to a radio talk show he was on during a book tour for his 2004 book Gay Marriage: Why it is Good for Gays, Good for Straights, and Good for America:
“Your guest,” he said, meaning me, “is the most dangerous man in America.” Why? “Because,” said the caller, “he sounds so reasonable.” In hindsight, this may be the greatest compliment I have ever been paid. It is certainly among the most sincere. Despite the caller’s best efforts to shut out what I was saying, the debate he was hearing—and the contrast between me and my adversary—was working on him. I doubt he changed his mind that day, but I could tell he was thinking, almost against his will. Hannah Arendt once wrote, “Truth carries within itself an element of coercion.” The caller felt that he was in some sense being forced to see merit in what I was saying.
The use of reason in an open dialogue forces us to consider the merit of what the other person is saying, and if the other person makes sense, their superior ideas gradually chip away at our prejudices. And many of those prejudices are based on factual errors about the target group, “factual misapprehensions and moral misjudgments born of ignorance, superstition, taboo, disgust,” says Rauch. “If people think you are a threat to their children or their family, they are going to fear and hate you. Gays’ most urgent need was epistemological, not political. We had to replace bad ideas with good ones.” That replacement can only happen in a free society in which open debate is allowed and ideas must compete for cognitive space in our brains.
I am not arguing that reason alone will get us there; we need laws to enforce civil rights. But our institutions are premised on law being grounded in reason, and the legislation being backed by rational arguments. Without that, there is no long-term sustainability to moral progress, as it is just a matter of might makes right. If your moral campaign depends exclusively on the powers of the state, then when the powers of the state change hands, those in power can just as easily change the law. To make morals stick you have to change people’s thinking. This is what happened with the abolition of slavery, with the expansion of women’s rights, and now with the recognition of full rights for the LGBT citizens of the world. And more than any other it is the Classical Liberal worldview grounded in reason and science that is bringing about this moral progress.