The Middle-Stack Hypothesis: A Bayesian Argument Against Cosmological Exceptionalism

We present a formal argument challenging the assumption that the observer’s scale (s_obs ~ 10^0 m) represents the global maximum of universal complexity. Standard cosmological models describe a "Complexity Ridge"—a local maximum where structural complexity (A_S) increases from the Planck scale to the biological scale, but decreases precipitously at the astrophysical scale. We propose that this ridge is an artifact of Substrate Confusion, distinguishing between Structural Assembly (A_S, measurable by the embedded observers) and Network Assembly (A_N, the invisible information-theoretic topology of causal interactions). By introducing a Generative Continuity Postulate, we contend that a sharp truncation of complexity at the observer's scale constitutes a statistically improbable discontinuity. We model the hierarchy probabilistically under a Uniform Observer Assumption, showing that for any non-zero prior on recursive structuring, the posterior probability of unobserved higher-order layers approaches unity. This reframes humanity not as the apex of a finite hierarchy, but as a functional substrate within an indefinitely recursive system.