Books of Christian apologetics books have often sold well in evangelical circles. Works by Lee Strobel and the late Tim Keller have risen to the top of The New York Times bestseller list because evangelicals, and other conservative Christians, want reassurance that their faith has a basis in reason. Keller and Strobel drew on data from history, science, and philosophy to make the case for Christianity’s reasonableness. This desire for a rational faith arises from the challenges that modern science and historical biblical criticism are thought to pose to Christianity.
In his forthcoming book The Search for a Rational Faith (Oxford, 2026), historian Daniel K. Williams, who teaches at Ashland University, traces the history of Christian apologetics from the English Puritans to modern-day evangelicals. Williams explores how, when faced with threats such as Enlightenment rationality, deism, and civic unrest, Christian apologists defended both the logical basis and the moral superiority of Christianity. Because attacks on Christianity were also seen as attacks on the moral order, defending the faith during times of civic unrest (the French Revolution, the civil rights movement, the Cold War, etc.) was viewed as essential to preserving America’s ethical foundations. Williams’s book examines both the social and intellectual undercurrents of Christian apologetics. I recently spoke with Williams over Zoom about the history of Christian apologetics and the current state of American higher education, and I have edited this interview for clarity and length.
Kenneth E. Frantz: Your book covers the history of Christian apologetics in America. Would you mind discussing what exactly Christian apologetics are and why you thought they were important to write about?
Daniel K. Williams: Christian apologetics is a pretty broad category. It covers any attempt to defend the faith against potential objections. It comes from the Greek word apologia, which was used for courtroom defenses. We can think of Christian apologetics as a way to defend Christianity and also to provide a reasonable argument for why Christianity or Christian truth claims are in fact true. So the term has covered a wide variety of things over the years. For much of the time period that I’m looking at in this book, Christian apologetics was very closely tied to what people called “Christian evidences.” That is, arguments that were almost like presenting courtroom evidence, but usually arguments based on a study of history and science, observations of the natural world that would lead one to believe that in fact the claims of Christianity, whether they were historical claims or whether they were moral and ethical claims, were persuasive. That is, that they were really grounded in something real. So the reason I called the book The Search for Rational Faith is because all of this apologetic enterprise was in some way engaged with the quest to make Christianity reasonable, rational—to say that in a world of science and in a world of potential objections to Christianity that in fact the Christian faith is reasonable, it’s rational to believe in it.
KEF: You do discuss a variety of different types of Christian apologetics, like evidentiary and presuppositional. You go into things like natural theology. Would you mind discussing the different types of Christian apologetics you discuss in your book?
DW: I begin the book with the seventeenth-century Puritans. The Puritans believed, like most Christians of the seventeenth century from a European background, that you could establish a reason to believe in God from observation of the natural world. In the late seventeenth century, that idea became codified in what people began to call natural theology, which was a new term of the late seventeenth century. Natural theology was a study of the evidence for God from the natural world.
Now, the idea of this goes back several centuries before the seventeenth century, but in the seventeenth century, this was codified in a study of arguments that today we might call the argument from design. The universe appears to have an order to it. The argument is that order requires a designer. But natural theologians of the late seventeenth, eighteenth, and early nineteenth centuries usually went further and argued that not only could the existence of God [be explained by] the natural world, but you could know something about God’s attributes. You could get to monotheism simply from an observation of the natural world. You could understand something about the power of the Creator and even the beneficence of the creator.
And so all of this, I think, reached a height at the very end of the eighteenth century with William Paley, whose textbook would be assigned in American and British colleges for several generations after that. Paley had a strong influence on Charles Darwin, before Darwin ultimately rejected some of the presuppositions of natural theology. Natural theology was closely related to Christian evidentialism, or evidentiary apologetics, in the sense that it was an attempt to look at evidence from the natural world for the existence of God. But Christian evidences went further and argued that in addition to simply knowing about the existence of God from the natural world, you could also apply the same sort of reasoning to the study of the Bible. You could look at the historical evidence that would either support or refute the Bible’s historic claims.
And in fact, the Christian evidentialist of the eighteenth and early nineteenth centuries would argue that a careful study of the Gospels would show that they were written by credible witnesses, trustworthy witnesses, who, if they were telling the truth, then gave evidence for something that could only be explained through an appeal to the supernatural. That is, Jesus’ miracles, and especially Jesus’ resurrection from the dead. If they were historic events that really happened in history, then they were evidence that Jesus in fact was from God and was more than just a man. In turn, they would argue you could prove the entire Christian message, by extension, and establish faith in both the historicity and divinity of the Bible.
This apologetic enterprise was in some way engaged with the quest to make Christianity reasonable, rational—to say that in a world of science and in a world of potential objections to Christianity that in fact the Christian faith is reasonable, it’s rational to believe in it.
Now, by the end of the late nineteenth century, but especially in the twentieth century, some of those ideas fell out of favor, first with more liberal Protestants and then even with a number of conservative Protestants moving away from evidentiary apologetics. And so, in the mid–twentieth century, especially in Reformed circles, there was the rise of presuppositionalist apologetics, which was based on the premise that perhaps apologists had conceded too much to ideas of the Enlightenment and rationality. And that maybe instead of using history and science to judge the truth of the Bible, that maybe it made sense to start with an assumption that the Bible was true. And then from there, once you had had assumed a conservative Christian theological approach as your basic presupposition, then to see if that way of viewing the world would make sense of life. And they argued that you could test the different worldviews by looking to see whether they interpreted all of the observable facts around them in a reasonable manner, in a cohesive manner. Were they able to make sense of the world without self-contradiction?
And they argued that you could not necessarily critique worldviews with a set of universally accepted principles, unlike what the Enlightenment thinkers had thought. The presuppositionalists were not willing to necessarily accept that. But they did believe that you could test a worldview by whether it was cohesive, whether it was free of self-contradictions, or whether it adequately explained to the world.
And on that ground they argued the naturalistic worldview fell apart, whereas the conservative Christian worldview could be supported through its internal cohesiveness. That idea took hold in a lot of conservative, Reformed evangelical circles in the mid-to-late twentieth century. It was associated especially with Cornelius Van Til, but then it was widely adopted by a number of people. And today there’s still a lot of presuppositionalists apologists out there, though there are other Christian apologetic approaches too that are popular.
KEF: And the through line seems to be that you moved from a focus on people interested in Christian evidences to people who viewed faith as a more personal or worldview thing. So why did you focus on that particular thread?
DW: I focused on that thread partly because that was the story of educated American Protestantism, particularly in the Northeast, in the late eighteenth and early nineteenth centuries. Especially by the 1820s, pretty much every Northeastern college required classes in Christian evidences or natural theology or both, that was considered an essential component of education. And by the late nineteenth century, those classes in Christian evidences were being abandoned in some places like Harvard, and eventually, at the beginning of the twentieth century, Yale. And while they may have continued in some colleges, like Oberlin, for slightly longer, nevertheless by the 1920s it was becoming difficult to find those classes anywhere.
And in turn, what replaced those classes were classes in the psychology of religion, classes that tended to talk about religious experience in the language of William James. And so as I was looking at the college curricula, I was seeing a story emerge, and it was a story that was very closely related to larger theological shifts in American Protestantism.
That is the shift from an early–nineteenth century evangelical Christianity that viewed the Bible as a literal record of history toward, by the late nineteenth century, a liberal Protestant theology that was grounded much more heavily in the assumptions of German historical criticism of the Bible, and the more liberal religion of people like Friedrich Schleiermacher. So, as a result, in Christian apologetics classes, there was a turn away from the quest to prove the historicity of the Bible, the quest to prove that Jesus really had done certain miracles, and therefore Jesus was someone who was the divine son of God, toward an attempt to prove or at least make a case for the superior quality of Christian ethics, especially as they were socially applied. Liberal Protestants borrowed a lot of that from William James, though William James was not exactly a Christian in the orthodox sense. In many ways, they Christianized William James, but their assumptions about how to arrive at faith very closely followed what William James had said in The Varieties of Religious Experience.
KEF: Would you mind talking about how exactly Christian apologetics was tied to certain crises in American history?
DW: The first crisis was in the early seventeenth century. That was an epistemological crisis in the aftermath of the Protestant Reformation and in the aftermath of the wars of religion, and also in the context of continued European exploration and conquest of the world, where Europeans were to a new degree encountering other religious systems outside Christianity. Altogether, it became more important than ever for people to prove their beliefs to themselves. Is there a way that you can know that what you think is true is really true?
And that crisis of epistemology is larger than just the Christian apologetic crisis. It gave rise to Descartes asking, How do I know even that I exist? (“I think therefore I am.”) But much of that quest did take the form of a Christian apologetic quest, where people wanted to find evidence so they could prove to themselves that yes, what they accepted as true could be rationally supported.
It also seemed to a certain extent that deism was on the rise in the United States, not just among the educated elite like Thomas Jefferson or Benjamin Franklin, but even by the late 1780s among members of the working class. So, Ethan Allen in Vermont was someone who was a strong theistic skeptic, who even produced a book about deism.
But in the immediate aftermath of the French Revolution, there was a bestselling book in America by Thomas Paine, who of course was the author of Common Sense. But Thomas Paine then wrote a book called The Age of Reason, which didn’t sell quite as widely as Common Sense, but nevertheless was widely distributed and was affordable for a lot of people. And it made the case against the Bible and against orthodox Christianity and argued in favor of a theistic skepticism, a belief that yes, there must have been some sort of creator who was rational, but there was really not a whole lot of value in the Bible. And it certainly was not a supernaturally produced book.
And that led to a lot of fear on the part of ministers and Protestant educators at the time. But I think what helped them make the case against Paine was that, even as that book was appearing in print, the French Revolution was taking a more violent and chaotic turn. And so in some ways, that move against deism on the part of Christian colleges was considerably bolstered by the belief that America needed to be a different sort of republic than France, that religion was vital to preserve society against social disorder and political anarchy or authoritarianism.
It became more important than ever for people to prove their beliefs to themselves. Is there a way that you can know that what you think is true is really true?
KEF: And another theme I picked up in the book kind of challenges the idea that Christianity isn’t compatible with academic life. You discuss the rise of the German university, and we also have this American model, which has a lot of focus on the Christian evidences.
DW: Yeah, so in the early years of American higher education, colleges were what we might think of today as small liberal arts colleges. They required every student to take the same subjects. So, the idea of specializing in a particular major actually didn’t come in until the late nineteenth century. In addition, they did not emphasize the acquisition of, or creation of, new knowledge. They were not research universities. The faculty who taught there were not expected to engage in the publish-or-perish model. Some of them did write books, but those books were not expected to be research-driven books. The Germans challenged the traditional medieval model of higher education, the liberal arts model of higher education, with a new focus on research. The research university was going to revolve around the pursuit of new knowledge through research, through a scientific enterprise.
And even the humanities would adapt themselves to that. So what historians began to do was seen as parallel to the scientific enterprise, a quest for finding new information in new ways. Americans, to a certain extent, became enamored with that. There was a quest for Ph.D.s in the late nineteenth century. At the beginning of the nineteenth century, no American had had a Ph.D., because the first Ph.D.s granted in the United States were not granted until the 1860s. And even in the late nineteenth century, with the exception of a very small number of places like Johns Hopkins University and Yale and a few others, it was difficult to find Ph.D. programs in the United States. The best Ph.D. programs, people thought, were in Germany, so large numbers of faculty who wanted to become leaders in their field went to Germany for education. And many of them came back with new understandings, not only of what the university should be, but new understandings of history and theology in the world at large. So, in particular, what they tended to adopt was a progressive understanding of history that fit the idea of a research model. And so in the 1880s, for example, there were places like Harvard and Yale that were very much trying to adopt that research university model. And eventually Princeton would, at the very end of the nineteenth century.
But there were also places like Williams College, for example, that very much saw themselves as a Christian liberal arts college in the 1880s. Now eventually a lot of those Christian liberal arts colleges would distance themselves from the Christian component of this, but for at least a generation or so, I think there was this dual model in place, where research universities existed alongside institutions pursuing that older model of education. And yet, because of the prestige of the research university, eventually the assumptions of the research university tended to color most of academia.
KEF: Right. In modern times, there does seem to be a renewal in the discussion of whether the university is doing its job or whether it’s undercutting the Christian moral fabric of the nation. Do you view that as part of the narrative, as a continuation of the narrative you’re telling in the book?
DW: Yes, and it is interesting to me to see the ways in which a number of Christian educators have pushed back against that research university model. So, there are conservative Christians who have said that Christians need to have research universities. Mark Noll, I think, made that argument in The Scandal of the Evangelical Mind, in 1994. And to a certain extent, I would say Baylor University’s pursuit of that R1 designation is an attempt to turn Baylor into that premier Christian research university.
But a much larger group of Christian educators and Christian colleges have openly questioned whether the research university model is really a very fruitful enterprise. At the very least, they would see its scope as considerably narrower than what maybe its champions in the late nineteenth century thought. And so I think we are living at a moment where there are significant components of Christian higher ed that are consciously trying to pursue something that is distinct from the research university. Among culturally conservative institutions that are trying to provide high quality education to a selective group of students from a strongly culturally conservative framework, and openly pursuing something that’s distinct from the research university, I would look to a place like, say, Hillsdale College. That’s not a research university, but it is trying to be a very selective institution.
KEF: You are a professing Christian, and this is a book about the Christian intellectual life. So, is there anything that you would hope other Christians would take away from this book?
DW: Well, I think some of the things that I think would be useful for Christians would be a realization that Christian apologetics has taken quite a number of different forms over the years, and that there’s not a one-size-fits-all. I think every form of Christian apologetics is based on particular assumptions that maybe make sense in a certain time period, and don’t necessarily always translate well beyond that particular context.
But also I would hope people would realize, after reading this book, that there is something worthwhile about the Christian apologetic project. And particularly there’s something worthwhile about asking questions about the rationality of the Christian faith. Most Christians have seen Christianity as not otherworldly, not as an irrational leap of faith, but rather as something that is grounded in history and the natural world that is in continuity with the rest of our lives. So that is a truth I think that Christian apologists at their best have tried to preserve, and it’s a conversation that I think is worth having.