Alan Sidelle's *Necessity, Essence, and Individuation* -(Sidelle, Alan, 1989) develops the most systematic contemporary defense of the view that necessity is a feature of how we describe the world rather than of the world itself. The argument descends from logical positivism (Ayer's *Language, Truth and Logic* -(Ayer, A. J., 1936) on analyticity, Carnap's "Empiricism, Semantics, and Ontology" -(Carnap, Rudolf, 1950) on framework-relativity, Quine's -(Quine, W. V. O., 1951) "Two Dogmas" as the critical pressure the tradition had to absorb) and Sidelle's contribution is to extend the analyticity treatment to *de re* modal claims (necessities about a thing itself rather than about its description). Saying water is necessarily H₂O is, on this picture, a decision about how to use “water” as a natural-kind term rather than a discovery about water.

The position has been pressed in different directions since. Sidelle's "Modality and Objects" -(Sidelle, Alan, 2010) develops the view in response to its critics. Ross Cameron's "On the Source of Necessity" -(Cameron, Ross P., 2010) and his subsequent work argue that necessity is grounded in linguistic and conceptual practice without being reducible to it. Amie Thomasson's *Norms and Necessity* -(Thomasson, Amie L., 2020) defends an adjacent modal normativism on which modal claims express norms governing concept-use rather than describing language-independent facts. Against the conventionalist tradition, Bob Hale's *Necessary Beings* -(Hale, B., 2013) develops the most sustained contemporary critique, and Jonathan Schaffer's necessitarian counter ("Laws for Metaphysical Explanation," -(Schaffer, Jonathan, 2017)) presses from a different direction.

The argument here does not contest the analyticity of selected modal claims. It contests the claim that all of them are. The structural conditions T, S, and Φ are not stipulated into necessity by linguistic decision; they are the conditions any stipulator must operate within in order to stipulate. (The formal regimentation of these structural claims in terms that satisfy Quine's extensionalist constraints is carried out at §[§2.10.1](<2.10.1 Three Distinct Logics.md>)–2.10.3; the bound-variable ontology is at [§2.8.3](<2.8.3 Not Physicalism.md>).) Any actual proposal and comparison is a structured cognitive and linguistic performance. That secures an act-side point about actual convention-making, not yet the object-side conclusion that every possible world instantiates the full temporal, spatial, and causal types. The global conventionalist still owes an account of the non-conventional resources used to formulate and apply the thesis. Three forms of the conventionalist move sharpen the reply at three resolutions.

*First.* The classical Sidelle -(Sidelle, Alan, 1989) form treats *de re* modal claims as analytic in disguise. “Water is necessarily H₂O” is not a discovery about water; it is a stipulation about how “water” is to be used in modal contexts, with the analyticity hidden by the *de re* surface grammar. The argument generalizes: every necessity is, on examination, a hidden analyticity, and the appearance of language-independent modal fact is the product of unrecognized linguistic decision.

The reply is internal. Stipulations are themselves entities, sequences of marks, sounds, or mental events whose individuation depends on extension, persistence, and contrast with other stipulations. Conventions are configurations within Reality, not grounds prior to it. To say “necessity is conventional” is to use a medium whose conditions are not conventional in any sense the position can recover. Sidelle anticipates the move and replies that the medium itself is conventional all the way down, but the regress closes the position rather than vindicating it. If “medium” is conventional, then the convention that fixes “medium” as conventional is itself a configuration, requiring the very conditions it purports to deflate. Quine's regress presses that conventions cannot alone generate all logical consequence, since applying them requires inferential resources. The structural account may use this against a global conventional reduction, but specifying those resources as the full T, S, and Φ types requires further argument rather than following from the regress itself. Hale's *Necessary Beings* -(Hale, B., 2013), ch. 4 presses this point at length: the conventionalist account requires modal vocabulary to state, and the modal vocabulary it requires is not stateable in the conventionalist's preferred terms.

*Second.* Cameron's -(Cameron, Ross P., 2010) refinement concedes the medium's structural conditions and presses the thesis at a higher level. Necessity is grounded in linguistic and conceptual practice in the sense that what makes modal claims true is the practice of using modal vocabulary in the way we use it, not in the sense that modal claims are reducible to claims about the practice. The grounding relation is asymmetric: modal facts hold in virtue of practices, but modal facts are not identical to facts about practices. The position survives the regress because it does not deny that practices have structural conditions; it grounds modality in practices and is silent on the structural conditions of practices.

The concession is real. The reply is that Cameron's position succeeds at the cost of being indistinguishable from the present account at the level where the present argument's claim applies. A concrete discursive practice ordinarily involves continuing practitioners, distinguishable acts, and temporal ordering. Those are conditions on such practices; calling them unrestricted modal conditions, and identifying them with the full loaded types, depends on the book's separate structural derivation. The grounding Cameron offers (modality grounded in practice) terminates at conditions on practice that are themselves necessary in every world in which practice exists. The present account names those conditions; Cameron's account leaves them implicit. The remaining disagreement is about whether the structural conditions are best described as conditions on linguistic practice in particular (Cameron) or on any configuration capable of hosting practice or anything else (the present argument).

*Third.* Thomasson's -(Thomasson, Amie L., 2020) modal normativism is a refined version. Modal claims do not describe modal facts; they express norms governing concept-use. “Water is necessarily H₂O” does not say anything about water; it endorses a norm about how the concept *water* is to be applied across counterfactual cases. The position is genuinely deflationary about modal facts without being committed to the regress-prone claim that modal claims are reducible to claims about language.

The reply tracks Thomasson's own framework. Actual norm-governed practices distinguish applications and often maintain standards across time. An abstract norm need not itself persist as a physical bearer or be applied in temporal sequence, so the practice-side structure should not be transferred automatically to the norm as an abstract object. Thomasson's normativism does not deny these conditions; it is silent on them, treating them as background to the normative analysis rather than as the locus of modal commitment. The present account makes them explicit. The conditions of a norm's being in force (proposed, applied, maintained in a practice) are what the structural roles secure, and any normativist account that disowns those conditions disowns the apparatus the account requires.

A kindred move presses from outside conventionalism entirely. Schaffer's -(Schaffer, Jonathan, 2017) necessitarianism argues that the laws governing metaphysical explanation are themselves necessary, but the necessity is not conventional: it is grounded in the structure of explanation itself. The present account agrees with Schaffer that the necessity is not conventional, and adds a constructive specification of what the necessity is grounded in: the structural conditions any configuration capable of being something must instantiate. Where Schaffer leaves the grounding at "the structure of explanation," the present account specifies the structure.

Two adjacent positions live elsewhere. Carnapian framework-deflationism is engaged at [§4.1.8](<4.1.8 Metaontological Deflationism.md>) (Metaontological Deflationism). Modal fictionalism, which deflates modal commitment by relocating it to a fiction rather than to convention, is engaged at [§4.4.4](<4.4.4 Modal Fictionalism.md>).

*What converges.* The conventionalist tradition has refined itself across thirty-seven years, from Sidelle's classical analyticity-extension (unstable on its own articulation, since stipulations have structural conditions it cannot recover) through Cameron's grounding-asymmetry (consistent with the structural account at the level of conditions on practice) to Thomasson's normativism (consistent at the level of conditions on norms). However the conventionalism is pitched (as analyticity-extension, grounding-asymmetry, or normativism) each form locates the source of □(T∧S∧Φ) in a derivative register (convention, practice, norm), while the register at which the modality holds is *a priori* / constitutive, supported by the fixed-domain S5 lift from the Cartesian witness together with the independent Structural Requirement and role-to-type premises, the T5/N register line [§4.1.1](<4.1.1 Rigid Designation.md>) records and [§4.1.2](<4.1.2 Two-Dimensional Semantics.md>) makes explicit.

Sidelle's 1989 book was written when the analyticity treatment of modality looked, after Quine's "Two Dogmas," like a project that had not survived the mid-century. The intervening decades have been a long argument that selected analyticities can be defended even if Quine's general critique stands. The argument has succeeded in part: there are conventional necessities, and the analyticity of selected modal claims is a stable position. What the long argument has not produced is a global conventionalism that survives examination of its own articulation. The conditions for the convention are not conventional. The structural roles are what any convention presupposes.


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← [4.1.6 Quinean Modal Skepticism](<4.1.6 Quinean Modal Skepticism.md>) | [4.1.8 Metaontological Deflationism](<4.1.8 Metaontological Deflationism.md>) →
