Hume's Law and Non-Arbitrary Ethics (MetaEthics)

Hume’s Law holds that normative conclusions cannot be validly derived from purely descriptive premises. This paper examines that challenge in relation to the Ethics of Metaphysical Congruence (MetaEthics), a framework that grounds moral evaluation in Reality, Awareness, Unity, and agency. It argues that Hume’s Law remains valid against attempts to derive command-like obligation from bare facts, but that it is often overextended into a broader rejection of objective morality. The central distinction is between obligation and moral evaluation. MetaEthics does derive moral evaluation from facts, but it does not derive external obligation from facts. Its third axiom is explicitly normative: morality is measured by congruence with Unity. The paper argues that this normative step is not arbitrary, because it grounds moral evaluation in the foundational trait of the non-optional Reality/Awareness field. At the level of agency, this criterion is expressed through the Non-Undercutting Principle, which identifies actions as congruent or incongruent according to whether they undercut the enabling conditions of agency. The conclusion is that Hume’s Law blocks one route from fact to morality, but not every route to objective and non-arbitrary moral evaluation.