Modernity, with its Enlightenment roots and subsequent philosophical developments, brought forth a radical rethinking of metaphysics and ethics. The optimism of reason and progress eventually gave way to an awareness of fragmentation—a disintegration of unified, tradition-based systems of thought. Philosophers such as Alasdair MacIntyre famously critiqued modern ethics for its disconnection from ancient and medieval traditions, and similar critiques can be found in the work of those who examine modern metaphysics. This essay explores how a group of thinkers—Étienne Gilson, David Oderberg, John Milbank, Edward Feser, William Desmond, and Gabriel Marcel—challenge modern philosophical approaches and propose a return to a more integrated, tradition-based understanding of reality and moral life.

Étienne Gilson, a prominent historian of philosophy and a staunch advocate of Thomistic thought, was among the first to articulate a powerful critique of modern metaphysics. He argued that modern philosophy, especially after the Cartesian turn, abandoned the central question of esse—the act of being itself. According to Gilson, Descartes’ emphasis on subjective doubt and the certainty of the cogito led to a fragmentation where metaphysics became an abstract, conceptual exercise detached from the concrete realities of existence. Gilson believed that by neglecting the rich tradition of medieval metaphysics, which saw being as an active, dynamic process imbued with purpose, modern thought had lost its capacity to engage with the true nature of reality. His work calls for a return to a realist framework, one that sees being as participatory and intimately connected to the divine order—a perspective that echoes the later critiques of modern ethics, which lament the loss of a unified moral vision.

In contemporary philosophy, David Oderberg stands out for his vigorous defense of Aristotelian-Thomistic essentialism. Oderberg criticizes modern metaphysical approaches that reject the notion of intrinsic essences and natural kinds, arguing that this rejection has led to a fragmented understanding of identity and purpose. For him, modern metaphysics has become overly reliant on modal logic and abstract reasoning that fails to capture the real, concrete nature of beings. Oderberg contends that the disintegration of metaphysical foundations parallels the breakdown of ethical systems criticized by MacIntyre—both resulting from a neglect of the traditions that once provided coherence and meaning. His call for a return to hylomorphism, the Aristotelian idea that every substance is a composite of matter and form, represents an attempt to restore a more robust framework that acknowledges the inherent order of the natural world.

John Milbank, a leading figure in the Radical Orthodoxy movement, offers a critique of modern metaphysics that is deeply rooted in theological concerns. Milbank argues that the Enlightenment’s secularization of philosophy has led to a dualistic split between the secular and the sacred, thereby impoverishing both metaphysics and ethics. By discarding the theological dimensions that once unified human understanding, modern thought has become a system of isolated and often contradictory ideas. Milbank’s critique extends to modern ethics as well, emphasizing that the loss of a shared, transcendent order has left ethical theories adrift, without the grounding of divine or natural law. His work advocates for a reintegration of theology with philosophy, suggesting that only by reclaiming a pre-modern, unified approach can we hope to overcome the fragmentation that characterizes both modern metaphysics and ethics.

Edward Feser, another prominent contemporary Thomist, directly confronts the legacy of modern metaphysics with a robust defense of scholastic realism. Feser argues that the modern break with Aristotelian thought—initiated by Descartes and furthered by empiricists like Hume and Kant—has led to a metaphysical void where abstract nominalism replaces the richness of realist ontology. In his view, modern metaphysics is marred by its inability to account for essential aspects of being, such as purpose, causality, and the nature of substance. Feser’s critique mirrors that of MacIntyre in ethics: just as modern moral theories have become unmoored from a coherent tradition, so too has modern metaphysics drifted away from the grounding insights of medieval philosophy. His work calls for a return to a framework that recognizes the intrinsic order and teleology of the natural world—a perspective that reaffirms the value of classical metaphysical categories and aligns with a broader, integrated view of human flourishing.

William Desmond contributes to this tradition of critique by focusing on the overly systematic and reductive tendencies of modern metaphysics. Desmond argues that in its quest for rational certainty, modern philosophy has imposed rigid conceptual systems on the world, thereby stripping away the rich, participatory quality of being. He criticizes post-Kantian metaphysics for reducing reality to mere conceptual schemes, neglecting the profound mystery and relational character of existence. For Desmond, the modern approach fails to capture the dynamic interplay between the self and the world—a loss that has profound implications for ethics as well. Without a sense of the mystery and wonder that underlies being, ethical life too becomes a matter of abstract calculation rather than an engaged participation in the fullness of existence. His work, therefore, echoes the calls of other tradition-based thinkers for a return to a metaphysics that is both deeply personal and fundamentally grounded in the concrete reality of life.

Gabriel Marcel occupies a unique position among these critics, bridging existentialism and traditional metaphysics. Unlike the more systematic approaches of Gilson, Oderberg, or Feser, Marcel’s thought is rooted in the lived experience of being. He critiques modern metaphysics for its impersonal and reductionist tendencies, arguing instead for a metaphysics that recognizes the profound mystery inherent in existence. Marcel distinguishes between “problems” and “mysteries.” Modern thought, he contends, treats existence as a series of problems to be solved through rational analysis. In contrast, Marcel insists that true engagement with being requires an acknowledgment of mystery—an openness to the transcendent and the relational aspects of life. His emphasis on participation and communion with being is a direct response to the alienation brought on by Cartesian subjectivity and Kantian formalism. Furthermore, Marcel’s ideas resonate with those of the Thomistic tradition. Like Aquinas, Marcel sees being as inherently relational, where meaning is not something constructed by isolated minds but is discovered in the interconnected web of human experience. This perspective challenges the modern dichotomy between the individual and the world, advocating instead for a vision of existence that is rich in depth, interconnectedness, and transcendence.

The critiques of modern metaphysics and ethics articulated by Gilson, Oderberg, Milbank, Feser, Desmond, and Marcel share a common theme: the modern departure from a tradition-based understanding of reality has led to fragmentation, abstraction, and a loss of meaning. Whether addressing the breakdown of moral systems or the disintegration of metaphysical foundations, these thinkers argue that the modern project has neglected the essential qualities of being—its mystery, relationality, and teleology. Gabriel Marcel’s thought, in particular, serves as a bridge between the existential and the traditional, offering a vision of metaphysics that is not only intellectually rigorous but also deeply connected to the lived experience of hope and communion. Together, these critiques invite a reexamination of modern philosophy, urging us to rediscover the rich, integrated traditions that once provided a coherent account of both the world and our place within it.

In essence, the call is for a philosophical renewal—a return to a perspective where ethics and metaphysics are interwoven with the fabric of human life, each informing and sustaining the other in the quest for truth, meaning, and flourishing.