The global rise of illiberalism and intolerance has, predictably, drawn sharp reactions from secular liberals. A common diagnosis points to religion, specifically Christian nationalism on the right and a “cult” of identity politics on the left, as the primary ideological drivers. This framing, however, may be fundamentally misaligned with the underlying forces at play.
What we are witnessing is not a resurgence of traditional religious authority, but rather the logical, if uncomfortable, culmination of certain secular philosophical traditions. The decline in theistic belief and religious practice has, in many cases, coincided with the very rise of these illiberal currents, both in the United States and globally. This suggests a more complex dynamic than a simple religious backlash.
The pressure point for liberalism, then, is not an external enemy of faith, but an internal erosion of its own philosophical bedrock.
The Secular Worldviews at Play
For decades, the intellectual landscape has been shaped by two dominant, albeit often unacknowledged, atheist worldviews. The first, broadly termed scientific materialism, posits that only the material world exists, knowable through sense perception and scientific method. It champions human capacity to understand and master reality, pointing to astonishing material progress. This view has become so pervasive that it is often taken as self-evidently true, the default context for public discourse.
Yet, this pervasive worldview carries inherent limitations that are rarely confronted. The most fundamental is the problem of induction, first articulated by David Hume: the general principle that all real knowledge derives from material facts perceived by the senses cannot itself be derived from such perceptions. It is a foundational assumption, not an empirically proven fact. This means scientific materialism, by its own standards, lacks a fully sanctioned basis for its most crucial tenets. Indeed, no general principle can be established from experience without already having the principle in hand. More critically, it struggles profoundly with the nature of experience itself. Consciousness, subjective awareness, the very act of internal thought—these are not material, not publicly observable, and thus, by the strictures of this worldview, often rendered non-existent or secondary. For those who live deeply within their own minds, this limitation becomes fatal; a worldview that denies the reality of internal experience cannot fully capture the human condition. The materialist frame, while excellent for prediction and utility, fails to capture within its scope all notable features of human experience.
The very legitimacy of deriving general principles from the particulars of experience can never be established from experience without already having the principle in hand.This intellectual void often leads to the second major atheist tradition: romantic idealism. This worldview, championed by figures like Nietzsche and Heidegger, begins precisely where scientific materialism falters—with the subjective, conscious agent. It valorizes emotion, imagination, and artistic creativity over reason and observation. Its ethics are those of authenticity: the greatest good is living true to one's subjective reality, constructing meaning from scratch. This rejection of ready-made, inherited responses to existential problems holds a powerful allure, particularly for those seeking to define their own path.
But romantic idealism, too, has its profound dangers. Lacking any provable universal truth, it revels in relativism. Historically, this tradition has been associated with darker political forces, inspiring figures from Rousseau (and the Reign of Terror) to Nietzsche (and the rise of fascism). On a personal level, the task of building meaning from scratch is fraught with anxiety and unhappiness, often holding the very goal of happiness in contempt. The material world, with its undeniable realities, cannot simply be willed away, and denying its external force is a recipe for misery.
This wasn’t about growth. It was about expectations.
It is into this philosophical vacuum that modern illiberalism has stepped. Consider the avatar of American illiberalism, Donald Trump. He is not defined by Christian faith; rather, he embodies a Nietzschean will to power, where truth itself bends to assertion. Similarly, significant cohorts among the highly educated left, often least likely to identify as religious, echo this romantic idealism. They view “objective truths” as mere expressions of power dynamics, tools of oppression, and champion identity and authenticity above universal liberal values. Both ends of the political spectrum, in their rejection of shared objective reality and their embrace of subjective will or identity, have become romantic idealists, posing a direct challenge to the very traditions of liberalism and scientific rationalism.
Liberalism's Foundational Vulnerability
The failure of these traditions to adequately respond is bound up with their own foundational problem. When liberalism functions smoothly, its practical benefits—delivering goods, fostering peace—are usually sufficient to quiet philosophical doubts. But when the system is perceived as failing, when the practical case for liberalism comes into question, secular liberals find themselves with little else to lean on. Early liberals like Locke understood that liberalism, much like empiricism, required a grounding in faith. For Locke, the concept of immortal souls and divine will conferred natural, inalienable rights that no government could legitimately deny. This metaphysical framework provided the very basis for individual freedoms and tolerance, even as it insisted on personal conscience in matters of faith.
Post-Hume, however, the invocation of metaphysical principles became an intellectual embarrassment. Theorists like Bentham dismissed natural rights as “nonsense on stilts.” Many liberals attempted to retain these abstract concepts without their original framework, or simply concluded that liberalism could function without foundations, so long as it “got the job done.” This pragmatic approach, while seemingly efficient, has left liberalism vulnerable.
By treating scientific materialism as the default, by demanding allegiance to a narrowly defined “reason” and “evidence,” and by attempting to banish metaphysical or spiritual discourse from public life, contemporary secular liberals are not upholding liberalism as its greatest proponents understood it. They are, in fact, stripping away the very concepts upon which any justification for liberalism beyond the purely practical must ultimately depend.
This is not a call for secular liberals to suddenly embrace God. It is, rather, a recognition that religious believers, who often possess a robust framework for understanding foundational truths and human dignity, should be seen as natural allies in the fight against irrational illiberalism. This doesn't necessitate abandoning secularism or liberalism. It means understanding liberalism's inherent limitations: it excels at allowing diverse conceptions of the good to coexist peacefully, but it was never designed to generate compelling conceptions of goodness itself. To ignore this distinction, and to dismiss all foundational belief as inherently illiberal, is to disarm liberalism in the face of its most potent, and often secular, challengers.
The core issue is not faith versus reason, but the search for a coherent, livable worldview that can adequately account for both the external material world and the internal ideational world, accepting an absolute foundation to things. Without this, the liberal project, for all its practical successes, remains precariously balanced.
