Bankruptcy of Physicality and Alterity in the Marriage Institution: The Limits of Identity Determination via the 'Identical Twins Bedroom Paradox' and the Realization of Subjective Accountability

The traditional discourse on identity, as articulated through the classical paradox of "Theseus's Ship," is fundamentally anchored in the quantitative measurement of materiality, spatial continuity, and historical persistence. However, when this framework is extended from inanimate objects to human subjects enmeshed in social relations, it encounters severe epistemological limits. This study establishes a conceptual model involving identical twins—whose genetic makeup, physical appearance, psychological memories, behavioral habits, and parental backgrounds are 100% identical—wherein only one twin is legally married to an outsider (the spouse). Set within a specific domestic scenario where both twins sit side-by-side in identical attire and posture, completely blocking emotional communication while simultaneously asking, "Which of us is your real spouse?", this research demonstrates the total collapse of external data-driven identity verification models. Furthermore, it reveals how the spouse's desperate emotional reactions and the formal classifications of state-legal apparatuses (judges, administrative officers, and official documentation) are systematically neutralized by the subjects' subversive performance of identity-switching. Ultimately, this study argues that neither external data nor third-party recognition can complete or verify human identity. Instead, the sole absolute criterion for existential identity is the "subjective accountability and self-awareness" through which an individual fully bears the legal, relational, and social consequences of their identity and actions.