The authors trace the modern instability of the concept back to a shift in how personhood is defined. In contemporary bioethical and legal discourse, they observe, personhood is frequently framed in functionalist or psychological terms: self-awareness, autonomy, linguistic capacity, or relational aptitude. Once those capacities become the criteria for personhood, the category becomes variable. Individuals unable to demonstrate them, whether because of developmental stage, illness, or disability, may be judged to fall outside the scope of full moral consideration. The article argues that this opens the door to selective inclusion, legal asymmetry, and a form of moral standing that is assigned by consensus rather than possessed intrinsically.

The article traces this instability to a departure from the classical definition of the person, formulated by Boethius as "an individual substance of a rational nature," which the authors argue has served for centuries as the cornerstone of Western philosophical anthropology because of its ontological clarity. It defines the person not through function, consciousness, or relation, but through being, as a distinct and irreducible subsistence endowed with rational capacity. Crucially, within this tradition, rational nature does not refer to the actual exercise of rational capacities at a given moment, but to the kind of being one is. Personhood therefore does not fluctuate according to the current manifestation of reason, self-awareness, or autonomy.

Thomas Aquinas developed this framework further, integrating it into his broader metaphysical system. For Aquinas, the rational nature of the person implies the presence of an immaterial principle capable of intellectual knowledge and free choice, and directed toward a transcendent end. The human person, as a composite of matter and form, possesses dignity in their being as rational and self-transcending. Within this tradition, the authors emphasize, personhood is not accidental or performative but essential: it pertains to what the being is in itself. The person is not a societal role or a granted status but a substantial reality, complete in itself and capable of knowledge and volition.

The article does not dismiss the twentieth-century critiques of this classical account. Phenomenology, existentialism, and various strands of personalism rightly insisted that dimensions such as affectivity, moral interiority, freedom, and relationality had not always received systematic attention in certain modern scholastic presentations of the person. Thinkers such as Edith Stein and Karol Wojtyła sought not to replace metaphysical accounts of the person but to deepen them through more attentive analysis of subjectivity and lived experience. The authors acknowledge these contributions as valuable, noting that Stein in particular sought to integrate phenomenological analyses of subjectivity with a realist understanding of being and personhood.

Yet the article identifies a conceptual risk in some of these developments. When approaches prioritize consciousness over substance, relation over being, and freedom over nature, they argue, the person risks being reduced to a constellation of observable, variable, and ultimately negotiable functions. Within such paradigms, to be a person is defined less by ontological identity than by the performance of specific capacities, whether relational, cognitive, or volitional. This reorientation shifts personhood from a stable metaphysical status to a functional or psychological condition. The authors stress that not all personalist thinkers embraced such a separation, and that what is needed is not the rejection of personalist intuitions but their reintegration into a metaphysical framework that affirms the person as a subsisting being, prior to and independent of function, relation, or recognition.

Building on this tradition, the article turns to Leonardo Polo, a contemporary philosopher rooted in the work of Aquinas, who maintains that consciousness, relation, and subjective experience presuppose a more fundamental ontological reality. At the heart of his proposal is the distinction between the personal act of being and human nature or essence. For Polo, personhood is not reducible to nature, but neither is it detached from it: personal being and human nature stand in a relation of distinction without separation. This distinction, the authors argue, allows Polo to avoid two opposite reductions, one that identifies the person exclusively with human nature, and another that grounds personhood primarily in consciousness, experience, or psychological functions.

Polo’s account of the personal act of being is not a static metaphysical substratum, the article explains, but a dynamic and transcendental openness, a structural orientation of the person toward knowledge, relationality, and transcendence. Freedom, in this context, is not merely the capacity to choose between alternatives but the capacity to transcend oneself through understanding, commitment, and ethical responsibility. A central strength of the framework is its careful distinction between the person and their faculties. Intellectual and volitional acts, while essential to human life, do not define personhood; they express a deeper metaphysical identity. Being precedes doing, and personhood precedes the manifestation of personal capacities. Polo also introduces a methodological innovation he terms the “abandonment of the mental limit,” a contemplative philosophical stance that acknowledges the limits of objectifying thought when applied to the person and respects the non-objectifiable character of personal being.

The authors then apply this framework to concrete bioethical and technological challenges. In debates over individuals with profound cognitive or physical disabilities, frameworks that define personhood through autonomy, rational function, or communicative capacity may regard such individuals as possessing diminished moral status or incomplete personhood. In the field of genetic manipulation for human enhancement, the person is implicitly conceived not as a metaphysical given but as a project to be optimized, a vision the authors link to posthumanist perspectives that reject essentialist accounts of human nature. In debates over artificial intelligence and synthetic consciousness, they observe, positions that treat the appearance of consciousness, relationality, or autonomy as sufficient for personhood could conceivably extend personhood to AI systems while withholding it from some human beings. What is at stake, they argue, is not merely the extension of personhood to new entities but the weakening of the conceptual link between personhood and human nature.

The article concludes that only an ontologically grounded conception of personhood, articulated in the realist tradition and enriched by Polo, can offer a stable criterion for human dignity amid technological and ethical change. Autonomy, relationality, and affectivity, on this view, are not the foundations of personhood but its expressions, presupposing a personal reality that precedes their manifestation. The authors are careful to note that their proposal does not assume realist metaphysics exhausts all possible ontological approaches to the person; rather, they argue that any adequate account of human dignity requires some conception of being capable of grounding the permanence and universality of personal worth. But its diagnosis is clear: where personhood is located in measurable traits or external recognition, dignity becomes contingent, and the most vulnerable human beings are the first to lose protection. To defend the person, the authors conclude, is in the final analysis to defend being.

Subject of Research: The ontological grounding of personhood and human dignity in contemporary bioethical debate

Article Title: The contemporary dispute over personhood: ontological roots and ethical implications

Article References: Frantz, P., Rego, F., & Barbas, S. (2026). The contemporary dispute over personhood: ontological roots and ethical implications. Humanities and Social Sciences Communications, 13(1), 1918. https://doi.org/10.1057/s41599-026-09198-1

Image Credits: AI Generated

DOI: 10.1057/s41599-026-09198-1

Keywords: personhood, human dignity, bioethics, metaphysics, Leonardo Polo, Thomas Aquinas, Boethius, personalism, posthumanism, ontology, functionalism, philosophy