Which story we tell about liberalism is a fraught and consequential choice. A common version, peddled by liberals and postliberals alike, is the Whiggish one: During the Enlightenment, Western man awoke from his dogmatic slumber to realize that the religious ideas of the Middle Ages were backwards and destructive. The rediscovery of the classical world in the Renaissance and ascent of individual conscience in the Reformation served as catalysts for a new world. Liberalism was thus molded from these raw materials by the hands of Thomas Hobbes and John Locke.

　　But this, according to Michael Bonner’s recent book The Crisis of Liberalism: The Origin and Destiny of Freedom, misses far too much. The foundational principles of liberalism did not emerge at the break of modernity, but were born from the theology of the Middle Ages. Liberalism’s core tenets, which thoroughly rely on Christian metaphysical assumptions, can be characterized by five axioms: “the primacy of the individual over the collective,” “unconstrained choice and free will,” humanity’s moral unity, the separation of the secular and religious spheres, and the potential for social and political improvement. Put more concisely: individualism, egalitarianism, universalism, secularism, and meliorism.

　　But the story of liberalism, according to Bonner, turned from patrimony to parricide when nineteenth- and twentieth-century liberals sought to plant their feet outside the Christian framework. Like a son who kills his father while expecting to continue enjoying his wealth and protection, these liberals unknowingly destroyed the life source of the ideas that they held most dear by jettisoning Christian doctrine. This godless liberalism, Bonner writes, has led to the ruin of the West by failing to respond meaningfully to the “deracination, dislocation, and disruption imposed on us by industrial capitalism and modern technology.”

　　Though Bonner at points becomes overzealous in his devaluation of early modernity, his assertion of the true roots of liberal thought is warranted and welcome, as is his categorization of Millian and Rawlsian liberalism as a sort of bastardized strand of Christian freedom discourse.

　　While most Westerners would accept some version of the liberal axioms listed above without batting an eye, many would struggle to justify them. To those with no recourse to God or Christian teaching, ideas like universal equality—which originates from the doctrines that man is made in God’s image and that all men are sinners from birth—can only be asserted as “self-evident.” Universal equality cannot be proved from within the liberal worldview any more than societal progress or the supremacy of the individual can.

　　The work Bonner does in deepening liberalism’s intellectual heritage is the book’s primary contribution to the liberalism discourse. There is nothing “self-evident” about all men being created equal, unless you live in a culture thoroughly saturated by Christian assumptions. The contrast is most stark with the ancient world. Exploitation of the weak by the powerful was not only common, but it was also accepted as natural and fitting. This is not an original observation—Bonner considers himself working in the tradition of scholars like Michael Allen Gillespie and Tom Holland—but it is made with unique power and breadth, drawing connections between modern and medieval thought which are rarely made in liberalism discourse.

　　Dante Alighieri, as Bonner tells us, argued during the thirteenth century in favor of a secular power concerned only with securing earthly happiness for its people through peace and stability. Marsilius of Padua contemporaneously built on Dante’s foundation to articulate the first doctrine of popular sovereignty. A century earlier, the mystic Joachim of Fiore wrote of an “imminent age of total human freedom” long before the enthusiasms of the Jacobins or Marxists. Modern themes of moral equality, freedom, and the “inward turn” spring from the pages of Thomas à Kempis’s fourteenth-century work The Imitation of Christ.

　　Bonner’s aim is to refute what he calls liberalisms “virgin-birth” myth. The Renaissance and Reformation were natural outgrowths of medieval Christendom, not breaks with it. Even when the great minds of the Enlightenment thought they were breaking with the past, they were utilizing the same tools and patterns of thought as their medieval forebearers. Descartes did not invent modern philosophy any more than Hobbes invented modern political theory or Francis Bacon invented the rejection of Aristotle. All were steeped in nominalist assumptions and categories. Descartes and Bacon were furthering a tradition stretching back to Peter Olivi. Hobbes’s Leviathan mirrored the papal absolutism of Innocent III. The exception is Machiavelli, who actually rejected medieval thought and, contra Patrick Deneen, favored returning to classical political ideas.

　　Bonner’s trajectory here is absolutely correct—the failure to acknowledge liberalism’s debt to medieval thought hamstrings any attempt to comprehend what liberalism actually is or to predict where it’s going. It makes nonsense of liberals’ fundamental claims about freedom and rights. If we want to understand liberalism, to say nothing of defending it, we must situate its precepts with historical and philosophical accuracy.

　　When ripped out of the Christian framework and stripped of Christian limits, freedom becomes anything to anyone, and we lose the ability to converse intelligibly about it.

　　Yet in some ways what Bonner offers is also an overcorrection. This becomes clear in the extremes his rhetoric reaches about historical continuity. While attacking the Whig story of modernity, he writes “there was no break with the past. The problems confronted by Petrarch and Luther, and everyone in between, were medieval problems, and their solutions were likewise medieval.” Later, Bonner suggests, “One may argue that medieval people did not in fact become modern at all, for we who are now living have still not left the medieval thought world.”

　　We have absolutely left the medieval thought world. Certainly, we can find precedent for most Western ideas in the Middle Ages—that is a natural consequence of living in the wreckage of Christendom, and the reason we cannot afford to discount medieval thought when wrestling with the modern condition. But there has been substantial intellectual change. Moderns do not view the world in the same way the medievals did. That transition didn’t occur overnight in the sixteenth century, but it has occurred. The work of intellectual heavyweights from C. S. Lewis to Charles Taylor demonstrates a gulf between the medieval and modern minds. Even if the ideas we consider modern were born in the Middle Ages, the deaths of countless others have altered the world fundamentally.

　　Much of this hinges on the lens through which one views historical change. There is absolutely a sense in which the distance between Petrarch and Luther is very small. Nobody told Luther he had left the Middle Ages. Yet there is another sense in which the gulf between them is vast. At the end of Petrarch’s life, Western Christendom was united in one church. At the end of Luther’s life, it was not. Bonner essentially treats the Reformation as a mere battle of recycled ideas, the umpteenth round between various camps within the church—Augustinian, Pelagian, Thomist, Ockhamist—which ended just as indecisively as all the others. But this is only justifiable if one excludes political, technological, social, and material changes from the calculus.

　　While Bonner’s is an intellectual history, and therefore not primarily concerned with material and political conditions, at a certain point the development of ideas is inextricably linked with external realities. As Sophia Rosenfield demonstrates in her book, The Age of Choice, ideas only gain purchase and affect daily life under conditions where their precepts are intelligible and imaginable. An idea’s acceptance or implementation further transforms the original idea. Ideas and the environments they inhabit are constantly acting on one another. There is no simple linear causation.

　　A good example is the idea of the autonomous individual. Such a notion could only emerge under conditions where choosing between a multitude of options, say amongst imported cottons in a store, was utterly commonplace. Mill’s ideas about female choice in The Subjection of Women would have seemed absurd to a medieval peasant, who had not experienced a culture “in which the experience of personalized choice-making and its small rituals and technologies … were starting to feel ordinary—and intuitively … linked to individual freedom.”

　　This is why Bonner’s drive-by treatment of the Reformation is questionable. Critique of the papacy was not new, but the European religious environment post-Reformation absolutely was. The transfiguration enabled people to imagine vast new possibilities in both the political and religious realms. Without the Reformation as a political fact, it is hard to imagine the Dutch overthrow of the Spanish in 1648, the English rejection of Catholic monarchy in the Glorious Revolution of 1688, and eventually the American Revolution in 1776. Without the mixing of denominations and sects in the Protestant countries, it is hard to imagine the development of religious freedom—instead of mere toleration—as a fundamental component of liberal belief.

　　One certainly can draw intellectual throughlines for all of the developments of liberalism back to Dante or Ockham, but you can also draw them back to Paul and Jesus, as Bonner himself does. While calling modern liberals and postliberals alike to account for their virgin-birthism is welcome, Bonner should be wary of neglecting the changes which did come with the dawn of modernity.

　　Continuing Bonner’s story, liberalism is a branch of what he calls the West’s “discourse of freedom” which, starting in the eighteenth century, began drifting away from its theological foundation. Paradoxically, the farther liberalism got from Christian doctrine, the more it became “like a rival religion in tension and conflict with institutional Christianity, its parent.” This not only manifested as a rival set of beliefs but as actual faux religions, invented to fill the obvious void. Early examples include the short-lived Cult of Reason, the Festival of the Supreme Being, and Auguste Comte’s Religion of Humanity.

　　None of these religious systems took hold and might seem rather distant from today’s liberalism. The Religion of Humanity was, however, hugely influential on John Stuart Mill. Mill had no time for the Comte’s rituals and ceremonies, but agreed with his fundamental premises. Mill’s utilitarian liberalism aimed at the improvement of humanity under the watchful eye of an educated clergy. While Comte admired medieval aesthetics, Mill admired medieval power and authority. Because men are not free by nature, they must be made free. If they resist—holding on to silly conventions and traditional values—then they are barbarians who must be coerced into “freedom” for their own good.

　　Bonner sees this form of Millian liberalism as setting the paradigm moving into the late-nineteenth and twentieth centuries, from Karl Popper to neoliberalism to the wars of democracy to the modern progressive activist. All profess faith in axioms they cannot prove, be they the market or the unstoppable march of progress, and all seek to apply their vision of freedom by force.

　　Thus we find ourselves today in a state of advanced parasitic consumption, wherein secular liberal ideas not only can’t sustain themselves but also furnish the means of their own undoing. We cannot make sense of where one set of rights begins and another ends, liberals struggle to justify their principles against critics both at home and abroad, and no one can agree on the meaning of “freedom.” While Bonner admits that his book is more diagnostic than prescriptive, he calls broadly for a return to Christian religion, arguing that “the quest for freedom has been most successful and beneficial when explicitly animated by theology, for it focuses, limits, and directs freedom toward a definite goal.”

　　That is the heart of the book. Western ideas about freedom emerged from Christian ideas about freedom. When ripped out of the Christian framework and stripped of Christian limits, freedom becomes anything to anyone, and we lose the ability to converse intelligibly about it. Bonner gets this absolutely right. While the book leaves some obvious questions unanswered—Is there something inherent in liberalism that leads its proponents to turn against their heritage? What role does nominalism play in perverting the Western discourse of freedom?—the ground he covers more than excuses any omissions. The crisis of liberalism, at its deepest, is a crisis of faith, and only a return to liberalism’s theological foundations will restore its coherence and power.