Dispositionalism is the nearest rival the account has, and it is nearest because it agrees with the account about the thing most other positions deny. It holds that possibility is grounded in actual reality rather than conferred by a plurality of worlds. Where (Lewis, David, 1986) makes ◇p true by the existence of a concrete world at which p obtains, the dispositionalist makes ◇p true by a property of something actual: a potentiality, a power, a disposition. (Vetter, Barbara, 2015) gives the position its book-length statement, grounding modality in object-level potentialities and dispensing with worlds as explanatorily basic; (Borghini, Andrea; Williams, Neil E., 2008) and (Jacobs, Jonathan D., 2010) run the article-length versions; (Pruss, A. R., 2011) develops a related actualist grounding. Behind them stands the dispositional essentialism of (Bird, Alexander, 2007) and (Mumford, Stephen, 2004), with (Mumford, Stephen; Anjum, Rani Lill, 2011) on the causal side.

A distinction has to be drawn before the engagement starts, because two different theses travel under one name. Dispositionalism about *laws* holds that laws are the structural expressions of the dispositional essences of natural kinds. That thesis is engaged at [§2.8.1](<2.8.1 Laws as Constitutive.md>), where it is one of four law-accounts the constitutive claim survives, and the engagement there is complete. Dispositionalism about *modality* is a different and more ambitious thesis: not that laws are grounded in powers, but that ◇ itself is. It is that thesis this section takes up, and it presses at the point [§4.1.10](<4.1.10 The Source of Possibility.md>) is defended.

The concession runs in full. The dispositionalist is right that a plurality of concrete worlds is an extravagant truthmaker for a modest claim; right that modal truths should answer to what is actually the case rather than to what is elsewhere the case; right that the possible-worlds apparatus is a formal convenience whose metaphysical reading was never obligatory. On the negative program the present account and the dispositionalist are allies, and [§4.4.1](<4.4.1 Modal Realism.md>) is where that alliance does its work. The disagreement is entirely about the positive one.

*First.* The reduction form runs directly at the Convertibility. Its claim is that ◇p holds if and only if some actual object has a potentiality for p, so possibility is not a structural feature of reality but a summary of what things can do. The Way–Possibility Convertibility ([§3.2.5](<3. Convergence.md>)) is then a redescription of the powers facts rather than a rival to them, and the structural triad is read off potentialities rather than presupposed by them.

The reply is that a potentiality already exhibits the triad, and exhibits it in the form the decomposition specifies. A potentiality is a directedness: it runs from a bearer, through a medium of manifestation, to an outcome that is not yet the case. That is an ordering with an asymmetry (the T-role), a distinctness between latency and manifestation without which nothing has been directed at anything (the S-role), and something that has the potentiality rather than the potentiality free-floating (the Φ-role). [§2.8.1](<2.8.1 Laws as Constitutive.md>) already makes the point on the laws side: a disposition without a persisting bearer, without relational extension through which it manifests, and without an interval between latency and activation is not a disposition. The dispositionalist has not produced an alternative to the way-structure. A potentiality is a way, individuated as one, and taking it as primitive does not remove what individuates it.

The reply is deliberately not the stronger one available. It does not say that necessitation *is* directional production, or that the manifestation relation supplies the content of T. That would give the structural conditions a second, analogical sense, which [§4.2.4](<4.2.4 Platonism.md>) forecloses. The claim is the deflationary one: the potentiality is described in the structural vocabulary because it instantiates the structure, not because the structure is a species of causal production.

*Second.* The primitiveness form concedes the exhibition and contests the direction of explanation. Grant that potentialities display direction, difference, and bearing; the dispositionalist may hold that potentiality is metaphysically primitive and the triad is a true description of primitives rather than a condition on them. Description does not establish priority.

The reply asks which side survives the removal of the other. A potentiality stripped of its directedness is not an undirected potentiality but no potentiality; strip the distinctness of latency from manifestation and there is nothing the potentiality is *for*; strip the bearer and there is nothing whose potentiality it is. The triad is therefore not a description that happens to fit but the individuation-condition of the primitive, and an individuation-condition is not posterior to what it individuates. The structural claim also takes a weaker form than the dispositionalist's own. The Convertibility runs as a convertibility, with neither *possibility* nor *way* reducing to the other, whereas dispositionalism is a reduction in one direction and therefore owes an account of its reduction base. What sits in that base is a property of an actual object, and a property of an actual object is specified from within the modal field in exactly the sense the Modal Exclusivity trilemma at [§4.1.10](<4.1.10 The Source of Possibility.md>) identifies.

*Third.* The coverage form is where the position is under most pressure from inside its own literature, and where the disagreement with the present account becomes visible rather than verbal. (Wang, Jennifer, 2015) presses that dispositionalism cannot reach possibilities for which nothing actual seats the relevant potentiality: alien properties, radically different physical regimes, possibilities concerning how things stood before there was anything with powers of the requisite kind. (Vetter, Barbara, 2015) answers with iterated and joint potentialities, extending the base by chaining what actual things can bring about.

The reply is that the internal dispute is settled, whichever way it goes, by asking whether there is something actual to seat the potentiality, and that question concedes the structural point rather than answering it. Both parties agree that possibility must be seated in actual reality. They differ only over whether the seat is a property of an object or the conditions any object-involving state already instantiates. At ordinary scope the difference is hard to see, because objects are available to bear the powers. At global scope the difference is decisive.

> [!premise]
> **The Bearer Problem** · *Premises*
>
> 1. Dispositionalism about modality: for any p, ◇p holds in virtue of the potentiality of some actual object (Reduction).
>
> 1. A potentiality is borne. There is no potentiality that is not the potentiality *of* something (Bearing).
>
> 1. Consider the possibility that there be objects at all.
>
> 1. By (1) and (2), that possibility holds in virtue of the potentiality of an object.
>
> 1. So the possibility that there be bearers presupposes a bearer, and the account has supplied its own manifestation-condition as its ground.
>
> 1. The dispositionalist must therefore either accept the circle at (5) or exempt the limit case from (1), which concedes that not all possibility is dispositionally grounded.

Neither horn is available at low cost, and the structural reading takes the second one without paying. What seats the possibility that there be objects is not a further object but the conditions any object-involving state instantiates: succession, distinction, and exchange are not properties an item has but the structure any item-involving state is. The dispositionalist's seat runs out at precisely the scope the argument of Chapter 2 operates at, and it runs out for a reason internal to the position rather than imported against it: powers are borne, and the global case has nothing to bear them.

A rejoinder is available and should be recorded. The dispositionalist may deny that *there being objects at all* is a genuine possibility requiring a ground, holding instead that it is necessary, so that no potentiality need seat it. That reply is not obviously wrong, but it is a concession in the relevant sense: it grants that something is necessary without being dispositionally grounded, and once one such necessity is admitted the reduction is no longer general. It also moves the dispositionalist onto the terrain of [§2.8.4](<2.8.4 Necessity Precedes Contingency.md>) and [§4.1.10](<4.1.10 The Source of Possibility.md>), where the question is no longer what powers ground but what a necessity that grounds nothing further can be. (Williamson, Timothy, 2013) reaches a structurally similar place from the opposite direction, and the answer [§4.4.6](<4.4.6 Necessitism.md>) gives applies here.

*What closes.* Dispositionalism is not refuted as an account of laws, and [§2.8.1](<2.8.1 Laws as Constitutive.md>) already grants it what it is owed there. As an account of modality it does not bypass the structural requirement but instantiates it, since a potentiality is individuated as a directed, differentiated, borne thing and is therefore a way rather than an alternative to ways. The order of explanation runs from the individuation-condition to the primitive, not the reverse. And the reduction does not reach the global case, because the possibility of there being bearers cannot itself be seated in a bearer. What the position establishes, and what the present account keeps, is that modality answers to actual structure rather than to a plurality of worlds. Where it locates that structure in the powers of things, the account locates it in what any thing with powers already presupposes.


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← [4.1.11 Pizzi's Impossibility of Nothingness](<4.1.11 Pizzi's Impossibility of Nothingness.md>) | [4.1.13 Modal Epistemology and the Remoteness Objection](<4.1.13 Modal Epistemology and the Remoteness Objection.md>) →
