The Misplaced Faith of Isaac Newton

In any list of the most influential people over the past 1,000 years, Sir Isaac Newton (1643–1727) always appears near the top. After all, he helped turn medieval thinking upside down by explaining why apples fall out of a tree. Well, at least that’s the popular view.

He was a brilliant and insightful scientist. By his mid-twenties, he had already made his most significant contributions to modern thought—the invention of calculus, discovery of the fundamentals of optics, and development of his famous law of gravity and three basic laws of motion. Virtually every aspect of modern life rests, in some way, on Newton’s findings. So it’s no surprise that everyone, even biblical creationists, wants to claim him as their hero. But we need to be careful.

Everyone’s Hero

The range of people who claim Newton is astonishing. At one end are anti-religious philosophers and scientists who are committed to naturalism. Naturalism is the philosophy that we can explain everything by natural laws and forces without reference to the supernatural (aka God). Adherents of this modern philosophy claim Newton’s work in physics provides the basis for their worldview. They say that at heart, Newton was a naturalist.

At the other end, creationists emphasize that Newton professed to be a Christian, denounced atheism, and had a high regard for the Bible. Indeed, Newton believed Moses’ account of creation in Genesis 1. In his magnum opus, Principia, which describes his laws of motion and gravity, Newton spoke glowingly about God: “This most beautiful system of the sun, planets, and comets, could only proceed from the counsel and dominion of an intelligent Being. . . . This Being governs all things, not as the soul of the world, but as Lord over all. . . . The Supreme God is a Being eternal, infinite, absolutely perfect.”

In between atheists and biblical Christians are deists, who also claim Newton. They believe there is a Creator, but he largely is uninterested in the affairs of men.

Who is right?

More Complicated Than That

Newton was a complex figure. This genius was very private and hated when duties of public life distracted him from his private studies. He was also passionately religious.

Few people know that Newton spent much more time researching and writing on theology than science. Most of his time was consumed with harmonizing biblical history and the chronology of other ancient peoples, as well as attempting to decode biblical prophecy. He ended up writing 10 times as much on theology as he ever did on math and science.

Newton thought that if he were remembered at all, it would be for his theological writings. Contrary to his expectations, Newton’s writings on math and science have been republished, studied, and revered, while most of his theological writings have gathered dust in obscure collections until very recently. In 1998 the Newton Project began a comprehensive edition of Newton’s nonscientific papers. Rob Iliffe, professor of history at Oxford and director of the project, summarized the findings in a 2017 book, Priest of Nature: The Religious Worlds of Isaac Newton.

A “Pure Religion”—Reason Gone Amok

The findings are shocking. Newton embraced the central Renaissance idea that we need to rescue the prisca sapientia, or “pristine knowledge,” of science and religion that has been perverted and obscured over time. That mindset drove the revival of classical learning in the 1400s, as well as the Reformation’s attempt in the 1500s to restore the true religion twisted by the medieval church.

But Newton took this rational approach even further than the Reformers. A central tenet of Newton’s day was that the true religion was at its core “rational.” This means that, through careful study, we can uncover what true religion was in the beginning, and restore it. Newton believed that men like Noah, Moses, and even Jesus restored this pure religion; but people kept perverting it. Newton wanted to help uncover this true religion for his day.

The problem is that Newton’s attempts to harmonize the Bible with history and prophecy led him to question basic doctrines. He came to believe that Christian theologians during the religious debates of Constantine’s day (early AD 300s) had rewritten historical documents to bolster their side. Newton set about to clean this up, and in the end, he rejected the Trinity.

Despite his vast intelligence and dedication to careful research and analysis, Newton let his false assumptions about what is “reasonable” guide how he interpreted the evidence. He filled in gaps with an elaborate story that made sense if a “pure religion” was corrupted in the past, even if he didn’t find direct evidence. No historian of any camp today would agree with Newton’s analysis.

Newton concluded that one of the earlier practitioners of the true religion was Noah, who correctly worshipped God and understood nature and the stars. He believed the ancient Egyptians employed the rationality of this original pure religion to achieve great engineering feats until idolatry and necromancy spoiled it. Moses, well-schooled in Egypt, supposedly reformed the religion; and the Israelites, too, for a while practiced it. However, the Jews soon polluted their religion, which once again required Jesus to reform the faith. Newton accepted that Jesus was the Messiah and would be coming again.

While committed to many of the teachings of Christianity and the English Reformation, Newton was convinced that Christianity needed further reform. Though he never stated it, Newton apparently thought he was best poised to lead this reformation. After all, his Principia established a rational basis for understanding the world, or rather reestablished it.

Restoring Pure Religion?

What was this true religion? According to Iliffe’s analysis, Newton thought the true religion at its essence was worshipping God as the Creator, and it included the careful study of the natural world. He emphasized careful use of reason to analyze nature empirically, avoiding conjecture and human “imagination.” Unlike deists, Newton believed in revealed truth and the value of organized religion. Iliffe concludes that Newton thought true Christianity required acknowledgment of God as the Creator, belief that Christ is the Messiah who rose the third day after his death, and observance of Christian morality.

Sound reasoning is essential (such as in rightly dividing God’s Word), but an overcommitment to “reason” above God’s Word can lead to profound error.

Is Iliffe’s interpretation of Newton’s writings correct in every detail? It’s hard to say—Newton was a complex man. Iliffe concurs with what others who have studied Newton’s theological writings have concluded: Newton rejected the Trinity, believing in the Arian heresy that Jesus is less than fully God. Apparently, Newton thought the doctrine of the Trinity was one of the corrupting influences that had infected the true religion.

New discoveries about Newton’s private beliefs provide some healthy warnings. First, we should be careful whom we make our heroes because we never know what embarrassing truths may someday come to light. Second, sound reasoning is essential (such as in rightly dividing God’s Word), but an overcommitment to “reason” above God’s Word can lead to profound error.

Third, Newton was right about one thing: theological pursuit—knowing God rightly—does matter more than science or any other pursuit. As with the writings of any other person, we need to evaluate whatever Newton wrote and accept only those things that are consistent with Scripture, which must be our standard for testing all things.