The Neural Péclet Number: Consciousness as Phase Transition, Seizure as T4 Runaway, and the Hard Problem as Conjugacy Budget Constraint

Neural information transport is governed by a Péclet number: Pe_neural = evoked signal amplitude / spontaneous noise, with consciousness present when Pe_neural > 1 (drift-dominated) and absent when Pe_neural < 1 (diffusion-dominated). Across 12 consciousness states (Spearman ρ=0.9663, p≈0) and 13 species (ρ=1.000), Pe_neural predicts consciousness level and cognitive complexity. Seizure onset is a T4 runaway with peak Pe=74.5× the critical threshold. The hard problem of consciousness is formalized as a conjugacy budget constraint I(experience;Y) + I(mechanism;Y) ≤ H(Y) — a structural limit, not a knowledge gap. Friston's free energy principle is shown to be identical to the void framework's drift-diffusion formalism under opacity, not merely analogous.