Objectivity by Invariance and the Limits of Physical Description

This note formulates a structural limitation of public physics within the Observer-Equivariance (OE) framework. Objectivity in physics is secured by invariance under admissible changes of perspective, formalized as a quotient from a space of observer perspectives to a shared structural domain. The central claim is that any description required to descend to this quotient cannot, even in principle, determine data that are local to a particular perspective.

The paper introduces a simple diagnostic—the Quotient Test—for evaluating proposed quantitative measures of consciousness. If a quantity is invariant under admissible transformations, it is necessarily structural and therefore correlates with the public quotient rather than with first-person presence in a specific perspective. Applied to information-theoretic proposals such as Integrated Information Theory, the analysis shows that such measures can at most be correlates, not identities, of phenomenal presence.

The result is a form of non-reductive structuralism: physics successfully captures what is shareable and intersubjective, while first-person presence is tied to the particular observer perspective that quotienting explicitly forgets. The argument is structural rather than epistemic and does not posit additional substances or entities beyond the standard physical framework.