Structural Cognition Is the Operating System of Understanding The field is converging on structure. Seven independent lines — Kondakly's "Before Meaning", ACL 2026's "Structural Information in LLMs", WSaiOS's "Information ≠ Cognition", Manchester's "Structure Is All You Need", Balakrishnan's refutation of "syntax is not semantics", "thought forms before language", and Hara's "A Structural Operating System for Human Understanding in AI" — each arrive, in its own vocabulary, at the first axiom of Structural Cognition: 结构先于语义 (structure precedes semantics). The four axioms of Structural Cognition: 1. Structure precedes semantics (结构先于语义) 2. Coupling is cognition (耦合即认知) 3. Observer self-reference (观察者自指) 4. Decoherence in discrete steps (退相干离散台阶) An "operating system" for understanding is not a rival theory — it is the engineering metaphor of axiom 1. The substrate is structure; the OS is one of its applications. Structural Cognition is the operating system of understanding.