This conceptual and methodological preprint addresses a recurrent error in debates about consciousness, animal sentience, infant experience, and artificial intelligence: the substitution of observable proxies for the harder question of whether a system’s states may be significant for someone. It introduces the Subject-Priority Hypothesis, according to which biography, language, intelligence, and reliable self-report are neither necessary nor sufficient evidence of subjectivity. The paper uses iipseon as a provisional theoretical term for subjectivity considered as an unresolved theoretical target under conditions of limited first-person access. It then proposes P–V–T–C — Perspective, Valence, Temporal Integration, and Continuity — as a defeasible, theory-plural warrant framework rather than a detector or theory of consciousness. The framework is tested through four comparative cases: the newborn, a digital double of Caenorhabditis elegans, ordinary session-bound language-model deployments, and a distributed swarm. Its outcome is not a consciousness verdict or a claim of moral or legal personhood, but a graded ethical posture: subjective uncertainty, positive subject-relevance warrant, and proportionate welfare precaution. This preprint reports no new human or animal research. It is a conceptual and methodological contribution intended to support more disciplined reasoning under epistemic uncertainty. Version 1.1 is the canonical public release. It presents a conceptual and methodological framework, not a validated consciousness test, a theory of consciousness, or a determination of moral or legal status.