Schaffer's priority monism holds that the cosmos is the one fundamental object and is prior to its proper parts. (Harrop, Stephen, 2024) develops a modalized version of priority monism (priority monism enriched with the claim that the priority relation between the cosmos and its proper parts holds with metaphysical necessity). Harrop argues that this enrichment entails the necessary existence of the actual cosmos and the impossibility of any concrete object not actually instantiated. The argument turns on the grounding-theoretic premise that the prior is fundamental in any world it grounds, combined with the modalization that the grounding relation holds necessarily. Where Harrop reaches a necessary cosmos from grounding-theoretic premises and modal closure, the present argument reaches a necessary Nature from the fixed-domain derivation and its Bottleneck defense (§[§2.1.4](<2.1.4 Modal Stability.md>)–2.1.5) and the bilateral-cogito chain (§[§2.2](<2.2 Cartesian Certainty.md>)–2.4). The two approaches converge on adjacent conclusions, but the theses are not identical. Harrop's thesis is that the *actual concrete cosmos* exists necessarily: a claim about the totality of concrete being. The present argument's thesis is that the *structural Conditions* T∧S∧Φ are necessary: a claim about the modal structure any cosmos must instantiate. The structural-conditions thesis is implied by the necessary-actual-cosmos thesis under the additional assumption that the actual cosmos instantiates T∧S∧Φ in every world in which it exists; the converse does not hold. A reader who finds Harrop's concrete-totality move too strong can accept the present argument's narrower structural-conditions claim without that commitment, and a reader who accepts Harrop's claim, together with that assumption, accepts the present argument's conclusion *a fortiori*. The structural specification the present argument adds is what Harrop's *necessary actual cosmos* would have to instantiate on either reading.


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← [2.9 Precedent Convergence](<2.9 Precedent Convergence.md>) | [2.9.2 Modal Limits](<2.9.2 Modal Limits.md>) →
