Flat Physicalism.

The one-sentence version

Flat physicalism is the thesis that higher-level regularities have no ontological depth beyond the microphysical states they supervene on — a wager that collapses the moment any observer must actually discriminate between those states. The discrimination itself costs energy.

Where the term comes from

The position has roots in Laplacian determinism and its modern successors in statistical mechanics — the view that macrostates are equivalence classes constructed by finite observers with limited resolution, not features of reality itself. Contemporary proponents include eliminative reductionists who treat biology, psychology, and social ontology as pending translations into physics.

Why it matters

Flat physicalism is the strongest version of the view that ontogony must defeat. If it were true, Landauer’s floor would be a brute engineering limit with no deeper significance, and the multi-level architecture of the real would be a projection of our cognitive limitations rather than a feature of the universe. The diagram shows precisely where that flat account runs out of explanatory resources.