Why Cognition Remains Bounded: A General Form of Cognitive Boundary

Why does cognition remain bounded even when generation can expand indefinitely? This paper shows that cognitive limitation is not a matter of insufficient knowledge or data, but a structural necessity. Under continuous generation, finite access, compression, and reuse, any system capable of stable cognition must induce indistinguishability across inputs. This indistinguishability forces partition, and once stabilized, produces a closed cognitive domain. We derive a minimal structural form of cognitive boundary: Boundary = (E, A, M, Π, Σ, K), where generation, access, mapping, partition, stability, and convergence together constitute the necessary components of bounded cognition. The central result is: Cognitive boundary is not a limitation of information, but a closure enforced by structure. Thus, increasing input alone does not expand cognition. A boundary persists as long as the underlying structure of distinction remains unchanged. This provides a structural account of why cognitive systems form stable yet limited domains of what can be known.