Historian Ethan Shagan wanted to understand why Martin Luther – in the Middle Ages! – claimed most people do not believe that God exists

This landmark book traces the history of belief in the Christian West from the Middle Ages to the Enlightenment, revealing for the first time how a distinctively modern category of belief came into being. Ethan Shagan focuses not on what people believed, which is the normal concern of Reformation history, but on the more fundamental question of what people took belief to be. Brilliantly illuminating, The Birth of Modern Belief demonstrates how belief came to occupy such an ambivalent place in the modern world, becoming the essential category by which we express our judgments about science, society, and the sacred, but at the expense of the unique status religion once enjoyed.

What led you to write this book?

Good works of history often begin with a chance discovery that sticks like a splinter in the historian’s mind: something weird or surprising in the historical record that demands an explanation. In this case, that oddity was something I found in Martin Luther’s collected writings: his claim that most people do not believe that God exists. This struck me as utterly outlandish. Besides the fact that more or less everyone in sixteenth-century Europe believed in God, Luther also wrote elsewhere that atheism was virtually impossible because knowledge of God is imprinted on all human souls. So what on earth was going on? Upon further research, I found other versions of this same bizarre claim popping up elsewhere in the sixteenth century. John Calvin wrote in his Institutes of the Christian Religion that anyone who follows their own passions in defiance of heavenly judgment “denies that there is a God”—the translator of the modern English edition changed this passage to “virtually denies that there is a God,” presumably because he thought the original must have been some sort of mistake. The radical spiritualist Sebastian Franck claimed, far more drastically, that “there is not a single believer on earth!” These remarkable and unexpected ideas were not written in obscure places, nor were they written by unknown people. So why had no historian ever written about them before?

These discoveries set me on a journey that has lasted seven years. I started with the intuition that “belief” itself had changed its meaning over time. Thus, for instance, Luther could say that everyone knows God exists, but he could still argue that most people do not believe God exists, because he took “belief” to be a more difficult condition. But from there I had to figure out what preexisting, medieval understandings of belief Luther was rejecting. Then I had to figure out how the different factions in the Reformation interpreted belief. And then, most importantly, I set myself the task of figuring out how a modern understanding of “belief” emerged. Hence this became a book about the birth of modern belief: a whole new way of imagining the relationship between religion and other kinds of knowledge, which we take to be absolutely timeless and natural but was in fact an invention of the seventeenth century and a touchstone of the Enlightenment. 

Can you explain a bit about the book’s argument? What do you mean by a modern category of belief? 

Belief has a history; the concept changes over time. We take it for granted that “belief” means private judgment or opinion. From that assumption, which we assume is timeless but is in fact profoundly modern, lots of other conclusions follow which seem equally unquestionable. For example, if belief is private judgment, then our beliefs might change over time in light of new evidence or further reflection. Likewise, if belief is opinion, then our belief on any particular issue might be probable rather than absolute: we might reasonably say we believe something if we think it’s likely, even if we’re uncertain. Most importantly, if belief is private judgment, then I might believe a religious doctrine in more or less the same sense that I believe that Lee Harvey Oswald acted alone, or that our sun is part of the Milky Way galaxy.

None of this would have been taken for granted in the Western tradition before the seventeenth century, and indeed a great deal of intellectual energy was poured into denying that any of it was true. Of course, people sometimes used the verb “believe” (credo in Latin, glauben in German, etc.) in a colloquial way—“I believe this peach is ripe,” or “I believe my husband loves me”—but a vast range of theology and philosophy was devoted to the proposition that this was totally different from belief in its proper, religious sense. To believe required an absolute, certain conviction, guaranteed to be true by reliable authority. Anything lesser or different could easily be denounced as unbelief, a failure of the mind and soul; anyone who believed wrongly, or insufficiently, or for the wrong reasons, or in the wrong way, might be taken not to believe at all. So my book is a history of how belief was freed from these constraints, creating the conditions in which religion could flourish in a secular age, but only at the cost of relinquishing the special status religion had previously enjoyed.

It seems intuitive that modern belief formed as a reaction against the Church, but how was it also a reaction against Luther and Calvinism?

Lots of people think that the Reformation produced religious liberty, because in the Reformation individuals—like Luther purportedly saying, “Here I stand, I can do no other”—insisted upon their own conscientious right to believe differently from the Roman Catholic Church. But this is quite wrong. Luther and his allies did indeed insist that their own beliefs were genuine, and that their ownconsciences were inviolable. But in the very act of making this claim for themselves, they insisted that all other beliefs were not simply false, they were not even beliefs at all. When early modern Protestants claimed the right to believe as they would, they were creating a new and exclusive category of belief to which others did not have access. So the Reformation did not inaugurate modern belief. Instead it produced a new kind of authoritarianism: whereas Catholics disciplined people to believe, Protestants accepted that belief was rare, and instead disciplined unbelievers. The reaction against these twin pillars of orthodoxy thus came from dissidents within both traditions. Modern belief emerged in fits and starts, not as a revolution against Christianity, but as a revolution from within Christianity by mutineers whose strained relationship to orthodoxy necessitated a more porous understand of belief.

How does the modern idea of belief travel through later intellectual movements such as the Enlightenment? Did it undergo changes there as well?

This is really a book about the Enlightenment, as much or more than it’s a book about the Reformation, because it was in the Enlightenment that modern belief truly emerged as a powerful force in the world. But the Enlightenment you’ll find in these pages may not be the one you expect.

First, it is an Enlightenment that is inclusive of religion rather than against religion. I do not deny, of course, that there was a “radical Enlightenment” which attempted, often quite explicitly, to undermine the claims of organized Christianity. But by far the more significant project of the Enlightenment was to reestablish religion on a new basis, to render it not only compatible with reason but a partner in the task of criticism which was at the heart of eighteenth-century ideas. The Enlightenment thus pioneered a question which we take for granted today, but which had received remarkably little attention previously: on what grounds should I believe? There were many different answers in the Enlightenment—as there remain today—but the task of Enlightenment religion was to tear down the medieval architecture of the mind which had strictly separated belief, knowledge, and opinion, and had thus made the question itself virtually meaningless. Enlightenment Christianity established what the Reformation had not: the sovereignty of the believing subject.

Second, my Enlightenment is not about the triumph of reason, but rather the triumph of opinion. Modern critics of the Enlightenment, on both the Left and the Right, often denigrate Enlightenment reason—and not without reason, if you’ll pardon the pun—as a false universal which allowed a new orthodoxy to establish itself as the natural frame of all argument rather than a peculiar argument in its own right. But this understanding of the Enlightenment, which takes Immanuel Kant as its avatar, misses huge swathes of late-seventeenth and eighteenth-century thought which instead privileged opinion, a kind of judgment that was particular rather than universal. In this book, I want to resuscitate an Enlightenment that privileged autonomous judgment rather than judgment constrained by someone else’s reason, and thus led to new kinds of spiritualism as much as it led to new kinds of scientism. At its worst, this modern spirit of autonomy produces the world of “alternative facts” and “fake news;” but at its best, it produces the conditions of freedom that allow for peace in a diverse society.

What is the relationship between the history of belief and secularization?

Every page of this book is engaged at least obliquely with the secularization question, but one of my key points is that secularization is the wrong question.

Secularization assumes that the crucial development in modernity is the creation of spaces outside or apart from religion; in modernity, this argument goes, religion has been relegated to a separate, private sphere. But by contrast, what I find is that modernity’s encounter with religion is not about segregating belief from the world, but rather about the promiscuous opening of belief to the world. Belief becomes, in modernity, not the boundary separating religious claims from other kinds of knowledge, but rather the least common denominator of all knowledge. Here my favorite example is the claim of many modern Christians that scientific knowledge—like the theory of evolution, for instance—is just another form of belief. This claim would have been literally nonsensical before the seventeenth century, because the whole point of belief was to preserve a special prestige for Christianity: science was a different beast altogether, belonging to different mental faculties and defended in different ways. The fact that scientific theories can now be understood as beliefs suggests that instead of thinking about the rise of a modern secular, we instead need to think about what happened when the walls separating religious belief from other kinds of knowledge-claims were breached.

What do you hope readers will take away from reading this book?

That belief has proliferated rather than waned in modernity, but only because the definition of belief has changed in our society to make it compatible with diversity, democracy, and freedom of thought. The old world of belief—where it was structured by authority, and where it functioned as an axis of exclusion to preserve orthodoxy—is dead and buried, and we should be thankful for its demise rather than nostalgic for the oppressive unity it once provided.