This paper presents a deduction within Homotopy Type Theory (HoTT) that proceeds from a single axiom – there is possibility – through fourteen steps to a formally derived coher- ence condition: any structurally adequate self-referential type in the presence of irreducible alterity has exactly one non-defective mode of operation – relation without reduction. This result is philosophically interpreted as the formal structure of responsibility. The deduc- tion runs in two parallel layers: a formal layer consisting of type-theoretic constructions, definitions, and derivations, and a philosophical layer providing interpretation of each for- mal structure. These layers are strictly separated. The point at which formal structure necessitates interpretive supplementation – the transition from ontology to epistemology – is explicitly marked. Schematic notation is identified as such. No additional axiom beyond the foundational one (and the standard framework of HoTT including the Univalence Axiom) is introduced. The strength of the concluding result depends on a definitional choice – the adequacy condition for self-reference – whose justification via Univalence is given and whose status as a definitional choice is made transparent.