The Risk-Bearing Subject of AI-Related Existential Risk to Humanity: From Species Survival to the Realization of Subjecthood under Conditions of Human Civilization

This paper is a work of conceptual engineering on the risk-bearing subject of AI-related existential risk to humanity, with implications for social epistemology, philosophy of technology, and AI risk governance. Existing discussions often understand “humanity” as Homo sapiens as a biological species and therefore define risk in terms of species extinction, permanent incapacitation, or future deprivation. This paper preserves that baseline framework but proposes a paradigm extension: while the risk-bearing subject remains humanity as an embodied species, the modes in which that subject can suffer existential harm should be extended from destruction or permanent incapacitation at the level of biological survival to the irreversible or difficult-to-reverse weakening of the foundational conditions under which humanity realizes subjecthood within civilization. The central question of this paper is: when we say that AI may threaten “humanity,” what exactly is the humanity at risk? The paper distinguishes two basic layers of possible harm to the same risk-bearing subject: the biological-survival layer and the civilizational-conditions layer. The former concerns the survival of humanity as an embodied species; the latter concerns the capacities through which humans know what is true, form judgment, bear responsibility, participate in institutions, create meaning, and act toward the future within an intergenerational common world. Within the civilizational-conditions layer, the paper further identifies the category-calibration mechanism: the mechanism through which foundational categories such as truth, evidence, responsibility, subjecthood, value, and meaning are clarified, maintained, and revised. The philosophical kernel is not an independent entity, but the category-calibration mechanism internal to civilizational conditions that maintains the operability of foundational categories. AI may weaken substantive human participation in the functional systems of civilization through deprivation by substitution or mediated reconfiguration, or may destabilize the calibration of foundational categories. The expanded definition proposed here is: AI-related existential risk to humanity refers to risks arising from the development, deployment, integration, or loss of control of AI systems that may irreversibly destroy the human species; render humanity permanently incapacitated or otherwise permanently foreclose humanity’s future; or undermine—irreversibly or in ways that are difficult to reverse—the foundational conditions under which humanity, as an embodied species, realizes its subjecthood within civilization. Risks at the civilizational-conditions layer are constrained by four thresholds: the risk must act upon foundational civilizational conditions, have cross-domain diffusion capacity, be capable of causing irreversible or difficult-to-reverse structural damage, and cause the first three kinds of harm to converge into overall damage to humanity’s capacity as a future-oriented subject. This paper does not offer a complete taxonomy of AI risks, a technical control scheme, or a policy checklist. It provides an ontological coordinate system for risk identification in AI safety, AI risk analysis, and AI governance: before discussing concrete risk types, governance pathways, or technical measures, we must first clarify the risk-bearing subject of “humanity” and the modes in which it can be harmed. Files and repository This Version 2 record includes the English V2 PDF, the Chinese V2 PDF, and the complete source package. GitHub mirrors are available in the Trantor Labs Research repository.