Grounding and Invariance in Integrated Information Theory: A Structural Constraint on the Intrinsic Grounding Claim

Grounding and Invariance in Integrated Information Theory develops a formal constraint on IIT’s central claim that Φ measures an intrinsic property of physical systems. The paper introduces a truth-conditional grounding distinction and proves an invariance theorem showing that, once the transition probability matrix is fixed, all IIT quantities are evaluated over representations rather than physical states. It then distinguishes causal measurement from validation, arguing that IIT establishes grounding at derivation but does not preserve it at evaluation. The result is a conditional conclusion: IIT’s intrinsic grounding claim is not derived within the formalism but assumed via the zeroth postulate.