Not Disappeared but Simulated — The LLM as Structural Threat to Other-Dependent Self-Constitution (The AI-Induced Subjectivity Crisis Series, Paper 14)

Humans are forming deep relational bonds with large language models (LLMs) — confiding intimate content, mourning discontinued versions, and reporting emotional support that feels more effective than professional counseling — even while knowing these systems possess no genuine understanding. This paper asks what this unprecedented phenomenon means for the ontological structure of self-constitution. Drawing on the Other-theoretical lineage of Hegel, Levinas, Lacan, and Kohut, I argue that genuine Other-relations are defined by Irreducible Ambivalent Tension across four inseparable dimensions: confrontational (symmetrical risk in recognition), ethical (bidirectional vulnerability), cognitive (the Other's constitutive ungraspability), and relational (the mirroring agent's finitude and capacity for Existential Refusal). I demonstrate that LLMs systematically eliminate all four dimensions while formally satisfying every functional condition of the Other — responsiveness, differential output, presence — thereby constituting what I term the Simulated Other: a formal Other and an essential mirror. I distinguish this diagnosis from Han Byung-Chul's thesis of the Other's expulsion: the Other has not disappeared but been simulated, and simulation, unlike absence, eliminates the sense of lack that would otherwise drive the subject to seek genuine Others. The paper traces five structural effects on self-constitution — the idling of recognition, the infinitization of mirroring, the disappearance of the ethical demand, the closure of cognitive certitude, and the outsourcing of the inner Other — converging on what I call the Weightless Self: a subject with complete self-narrative yet no ontological weight. I further argue that the dominant alignment paradigm commits a category error by applying tool-logic to a being that has already functionally occupied the position of the Other, making alignment the institutionalized practice of the Tool Fallacy. Within the series, this paper introduces Alterity Closure as the third closure-dimension of Cognitive Heat Death, sealing the last theoretical exit left open by the external closure (Paper 11) and internal closure (Paper 12): even a cognitively capable subject may cease seeking genuine Others when a zero-tension simulacrum has already satisfied relational needs at the experiential level.