In The Church of Saint Thomas Paine, historian Leigh Eric Schmidt unfolds a forgotten episode in the history of American religion: the brief rise and fall of the “Religion of Humanity” in the late nineteenth and early twentieth centuries.

Inspired by the French positivist Auguste Comte and the American transcendentalist Ralph Waldo Emerson, and taking the eighteenth-century freethinker Thomas Paine as a kind of patron saint, a small group of Americans attempted to found a rationalist “religion” with science as its highest authority. They started congregations in cities like New York, Chicago, and Portland; they held meetings on Sunday mornings to compete with Christian rivals; they even wrote catechisms and ran Sunday Schools to indoctrinate new members. All confidently believed they were the vanguard of a new, secular religion that would displace Christianity and promote human progress.

But the new religion failed. The congregations attracted few followers; typically, as one British humorist wrote, these were churches “of three persons, but no God.” Most fizzled out or merged with larger groups like the Unitarians. Other than cranks who seemed as credulous as the believers they mocked, Americans had little interest in Comte’s wedding and funeral ceremonies or the relics of secular saints. (In 1905, after a long quest, a small group of freethinkers placed something they claimed to be a piece of Thomas Paine’s brain, sold to them for five pounds by an obscure London bookseller, in a monument in New Rochelle.)

Schmidt shows that rationalist congregations failed because organizers never resolved basic inconsistencies. Rationalism valued science and rejected metaphysics. Why, then, collect relics and meet weekly for thinly disguised worship services? Moreover, rationalism “made intellectual independence and the displacement of all religious authorities foundational to its platform.” Paine himself had railed against organized religion, famously declaring, “my own mind is my own church.” Similarly, although Emerson had prophesied a new religion with “science” for its “symbol,” he insisted on individual spiritual autonomy: “I go for Churches of one.” What, then, was the point of joining a new religion, even a rationalist one? People who share only a commitment to radical individualism and an opposition to religious orthodoxy are unlikely to form an enduring community.

Schmidt offers memorable portraits of several turn-of-the-century rationalists, one of whom turns out to be a distant relative of mine. M. M. Mangasarian, my great-granduncle, was an Armenian born in Ottoman Turkey in 1859, and later educated for the Christian ministry by American missionaries. He immigrated to the United States in the late 1870s, graduated from Princeton Theological Seminary, and got himself a pulpit in a Presbyterian church in Philadelphia.

He began as a conventional Victorian Protestant. But after a few years he decided that he could no longer accept Calvinism and resigned from his position, intending to found a new, liberal Christian congregation.

However, he soon discovered that he could no longer accept Christianity at all—or, indeed, any revealed religion. “I bow my head to a greater Power than Jesus,” he wrote, “to a more efficient Savior than he has ever been—Science!” For many years, he belonged to Felix Adler’s Ethical Culture movement. But he eventually left that group, too, when he thought it had become too soft on theism. The only solution was to commit to “uncompromising Rationalism.” So, in 1900, he founded a new body, the “Independent Religious Society (Rationalist) of Chicago.”

His career took off. Something like 1500 or 2000 people attended the society’s Sunday meetings in Orchestra Hall to hear him lecture. He published several books, including a New Catechism (“science is the highest authority in matters of faith and conduct”) that received favorable attention from secularists like George Holyoake in England, and a popular book arguing that Jesus had never existed—an odd claim for a rationalist to make, since the historical evidence for Jesus is overwhelming. He espoused fashionable progressive views, including feminism and eugenics. According to Schmidt, Mangasarian’s Independent Religious Society was “one of the most successful ventures in congregation-building among freethinking, humanistic liberals.”

And yet, in less than twenty-five years, it was over. In 1922, the society went out of business and was absorbed by the Western Unitarian Conference. Earlier in his career, Mangasarian had rejected Unitarianism because, like the Ethical Culture movement, it compromised too much with Christianity and the supernatural. Now, however, he praised Unitarianism’s “history” and “institutions.” As Schmidt writes, Mangasarian’s decision to join the Unitarians was at least in part a “concession about the limited prospects” for a free-standing, rationalist group dedicated only to science.

Schmidt ends with an epilogue on rationalist groups today. Like their nineteenth-century antecedents, he observes, they remain a fringe phenomenon. That’s not to say that traditional, organized religion is thriving. Quite the contrary: Although Schmidt doesn’t address the topic, the last thirty years have seen an explosion in the number of Americans who belong to no organized religion—the so-called “Rise of the Nones.” Like Mangasarian and the others Schmidt describes, the Nones find traditional religious authority stultifying. Unlike the rationalists, however, they do not reject the transcendent. The large majority of Nones claim to follow their own spiritual paths, combining elements of different faith traditions into private, do-it-yourself faiths, what Tara Isabella Burton aptly calls “Remixed” religions. Moreover, unlike the rationalists, Nones have no interest in joining new groups. Rationalists like Mangasarian rejected belief, not belonging. For today’s Nones, it’s just the opposite.

There’s much to criticize in today’s Remixed religions, including solipsism and superficiality. But believing Nones are likely to have more purchase in American society than hyper-rationalists like my great-granduncle ever could. In acknowledging and pursuing a transcendent reality, they are responding to something deep in human nature—and in American culture, going all the way back to the Puritans. For Americans, a church devoted completely to science and the here-and-now will always be a hard sell. “The religion of secularism,” to use Schmidt’s phrase, will always be an oddity, populated by eccentrics: “a sectarian peculiarity, within a God-blessed nation.”

Mark L. Movsesian is the Law School’s Frederick A. Whitney Professor of Contract Law and co-directs our Center for Law and Religion. This piece published originally at First Things on December 7, 2022.