Sen. Ted Cruz, who recently announced his candidacy for the Republican presidential ticket, thinks, like many conservatives, global warming isn’t happening. As he said on Seth Meyers’ talk show on March 16, “Satellite data demonstrate for the last 17 years there’s been zero warming, none whatsoever.”

It’s no surprise that Cruz picked that figure: 17 years ago was 1998, an “El Nino” year, when global temperatures were artificially elevated after which they returned to their normal gradually increasing rate. When you look at all the data published by the National Oceanic and Atmospheric Administration (not just the cherry-picked data that fits neatly into a political ideology), the long-term increase in global temperatures is unmistakable.

I’m not saying that liberals don’t have their own science problem. They have no trouble railing against GMOs and nuclear power, and they ignore the obvious benefits of fossil fuels to pull impoverished people into the age of prosperity (burning cow pies in makeshift fireplaces in mud huts is not an efficient means of heating homes or producing wealth). Don’t even get me started on “anti-vaxxers,” a vocal and determined group that seems to make up a small minority in both parties.

The Founding Fathers would be ashamed.

Three centuries after the Age of Reason and the Enlightenment gave birth to the principles that drove the American Revolution, we are forgetting that it is scientific facts that should settle such issues, not partisan politics. In these examples the data are quite clear and the jury is in: Global warming is real and humans caused it, GMOs are safe and we need all the sources of energy we can get to meet the demands of our ever-increasing population. Why, then, are we so politically divided on these points? It seems that, in our rush to find support for what we want to be true (it’s an effect called “motivated reasoning,” which is driven by the confirmation bias in which we seek and find confirming evidence for what we already believe and ignore or rationalize away disconfirming evidence), we have forgotten how to discern what actually is true. We’ve forgotten how to use science and reason to solve problems and instead we’ve turned to moralizing about scientific issues.

Here’s why we, particularly Ted Cruz, should be very worried about this: The influx of scientific principles into society led not only to the triumph of science, but also to the moral progress of the Western liberal tradition—yes, even to Cruz’s prized “exceptional” American democracy. Since the Scientific Revolution of the 16th and 17th centuries, intellectuals sought to emulate great scientists such as Galileo and Newton in applying the rigorous methods of the natural sciences to solving social and political problems. Enlightenment natural philosophers such as John Locke, Thomas Jefferson, Benjamin Franklin, Alexander Hamilton, James Madison and Thomas Paine—America’s Founding Fathers—placed supreme value on reason and scientific inquiry, which in turn led them to prize human natural rights, equality, and freedom of thought and expression.

In fact, America’s own democracy is rooted in reasoned analysis and scientific inquiry. Based on his medical training and the influence of many of the biggest scientists of his generation, Locke reasoned that all people should be treated equally under the law. He then sought to verify his theory empirically; and his theory has endured, as countries that practice it have flourished.

Consider how science has affected other leading thinkers whose work created the modern world. Thomas Hobbes’s Leviathan, recognized as the most influential political treatise ever written, begins with atoms in motion and builds on observations and first principles to devise a rational- and empirical-based social system (he called himself the Galileo of civil society). Montesquieu, in his book Esprit des Lois (The Spirit of the Laws), invoked Newton when he compared a well-functioning government to “the system of the universe” that includes “a power of gravitation” that “attracts” all bodies to “the center” (the monarch), and he employed the deductive method of Rene Descartes: “I have laid down first principles and have found that the particular cases follow naturally from them.” By “spirit” Montesquieu meant “causes” from which one could derive “laws” that govern society. “Laws in their most general signification, are the necessary relations derived from the nature of things,” he wrote.

François Quesnay—physician to the king of France—and his followers (the French physiocrats) undertook a systematic study of the economy from which they gathered empirical evidence and derived rational principles that underlie how economies grow or shrink as a function of government policies. This led the Scottish Enlightenment moral philosopher Adam Smith to compose the founding text of economic science, which everyone knows as The Wealth of Nations. Its full title, in fact, is An Inquiry into the Nature and Causes of the Wealth of Nations. It is a scientific inquiry to discover the true nature and causes of wealth, straight out of the tradition of the scientific revolution.

So you see, for nearly three centuries, we have been using science to determine such moral values as the best way to structure a polity, an economy, a legal system and a civil society, in the same way that physicians have developed improved medical science and epidemiologists have worked to build better public health science in order attenuate plagues, disease and other scourges of humanity. Are we supposed to just give up on that now?

Ever since these great Enlightenment scientists undertook a research program of understanding how human societies work and what we can do to improve them, the moral arc has been bending ever more toward truth, justice and freedom. The reason our European ancestors in the Middle Ages strapped innocent women on a pyre and torched them was because they believed that witches caused crop failures, weather anomalies, diseases and various other maladies and misfortunes. Today, we refrain from burning women as witches not because our government prohibits it, but because we have a scientific understanding of these misfortunes and maladies. What was once a moral religious issue is now a nonissue, pushed out of our consciousness—and our conscience—by a naturalistic, science- and reason-based worldview.

Science and reason have debunked a number of such myths, such as that gods need animal and human sacrifices, that demons possess people, that Jews cause plagues and poison wells, that some races are inferior to other races, that women are too weak to run countries or corporations, that animals are automata and feel no pain, that kings rule by divine right, and many other beliefs no rational scientifically-literate person today would hold.

We are not so far away from these beliefs as we think we are.

Republican and Democratic leaders might not see the connection between current controversies like global warming and GMOs and their historical antecedents such as witch crazes and slavery. But our modern concepts of governance arose out of this drive to apply reason and science to any and all problems, including human social problems. In the long-run we need to set aside bipartisan politics that divides us on such issues as climate change, energy policy and vaccinations, and do what we’ve been doing in applying science and reason to solving social problems so that we may continue to bend that arc ever more toward the betterment of humanity. It’s what the Founding Fathers would want.