Online research in philosophy

: It is widely thought that dispositional properties depend upon categorical properties; specifying the nature of this dependency, however, has proven a difficult task. The dependency of dispositional properties upon categorical properties also presents a challenge to the thesis of Physicalism: If the physical sciences only tell us about the dispositional properties of the objects they study and if dispositional properties depend upon categorical properties, then it appears that there will be kind of property—categorical properties—that will escape description by the physical sciences. This paper argues that a new theory of dispositional and categorical properties, a theory put forth by C.B. Martin and John Heil, solves both of these problems: It presents a way of understanding the sense in which dispositional properties depend upon categorical properties that has major advantages over more popular accounts of this dependency and it also provides a new and interesting Physicalist response to the challenge presented by categorical properties.

This paper discusses the relationship between dispositions and laws and the prospects for any analysis of talk of laws in terms of talk of dispositions. Recent attempts at such a reduction have often been motivated by the desire to give an account of ceteris paribus laws and in this they have had some success. However, such accounts differ as to whether they view dispositions as properties fundamentally of individuals or of kinds. I argue that if dispositions are properties of individuals, we cannot give a complete account of ceteris paribus laws. Alternatively, if dispositions are properties of kinds, any reductive analysis of laws would require an extension of the notion of the dispositional beyond its usual meaning so that in effect there can be no reduction of laws to dispositions as traditionally understood. An attempt to reduce the nomological to the dispositional is therefore not the way to provide a unified account of traditional and ceteris paribus laws.

Dispostions, such as solubility, cannont be reduced to categorical properties, such as molecular structure, without some element of dipositionaity remaining. Democritus did not reduce all properties to the geometry of atoms - he had to retain the rigidity of the atoms, that is, their disposition not to change shape when a force is applied. So dispositions-not-to, like rigidity, cannot be eliminated. Neither can dispositions-to, like solubility.

Possession of any actual physical property depends on the ambient conditions for its bearers, irrespective of one's particular theory of dispositions. If 'self-sufficiency' makes a property intrinsic, then, because of this dependence, things in the actual world cannot have an intrinsic physical resemblance to one another or to things in other possible worlds. Criteria for the self-sufficiency of intrinsic properties based on, or implying indifference to both 'loneliness' and 'accompaniment' entail that no self-sufficient property can require its bearers to be extended in space or time, yet all physical properties of concrete objects do require this. These outcomes undermine the vindication of physicalism claimed by neo-Humeans for their metaphysical project. For physical properties dependent on ambient conditions cannot supervene on intrinsic properties independent of ambient conditions: when ambient conditions change we get a change in the former without a change in the latter.

Simon Blackburn has argued that science finds only dispositional properties. If true, this is surprising: we think of the world as containing categorical properties too. But Blackburn thinks that our difficulties go further than this: that the idea of a world containing just dispositional properties is not simply surprising, but incoherent. The problem is made clear, he argues, when we have a counterfactual analysis of dispositions, and then understand counterfactuals in terms of possible worlds.

General metaphysical arguments have been proposed in favour of the thesis that all dispositions have categorical bases (Armstrong; Prior, Pargetter, Jackson). These arguments have been countered by equally general arguments in support of ungrounded dispositions (Molnar, Mumford). I believe that this controversy cannot be settled purely on the level of abstract metaphysical considerations. Instead, I propose to look for ungrounded dispositions in specific physical theories, such as quantum mechanics. I explain why non-classical properties such as spin are best interpreted as irreducible dispositional properties, and I give reasons why even seemingly classical properties, for instance position or momentum, should receive a similar treatment when interpreted in the quantum realm. Contrary to the conventional wisdom, I argue that quantum dispositions should not be limited to probabilistic dispositions (propensities) by showing reasons why even possession of well-defined values of parameters should qualify as a dispositional property. I finally discuss the issue of the actuality of quantum dispositions, arguing that it may be justified to treat them as potentialities whose being has a lesser degree of reality than that of classical categorical properties, due to the incompatibility relations between non-commuting observables.

This paper develops two ideas with respect to dispositional properties: (1) Adapting a suggestion of Sungho Choi, it appears the conceptual distinction between dispositional and categorical properties can be drawn in terms of susceptibility to finks and antidotes. Dispositional, but not categorical properties, are not susceptible to intrinsic finks, nor are they remediable by intrinsic antidotes. (2) If correct, this suggests the possibility that some dispositions—those which lack any causal basis—may be insusceptible to any fink or antidote. Since finks and antidotes are a major obstacle to a conditional analysis of dispositions, these dispositions that are unfinkable may be successfully analysed by the conditional analysis of dispositions. This result is of importance for those who think that the fundamental properties might be dispositions which lack any distinct causal basis, because it suggests that these properties, if they exist, can be analysed by simple conditionals and that they will not be subject to ceteris paribus laws.

Many philosophers think that dispositions are necessarily intrinsic. However, there are no good positive arguments for this view. Furthermore, many properties (such as weight, visibility, and vulnerability) are dispositional but are not necessarily shared by perfect duplicates. So, some dispositions are extrinsic. I consider three main objections to the possibility of extrinsic dispositions: the Objection from Relationally Specified Properties, the Objection from Underlying Intrinsic Properties, and the Objection from Natural Properties. These objections ultimately fail.

Dispositional essentialists argue that physical properties have their causal roles essentially. This is typically taken to mean that physical properties are identical to dispositions. I argue that this is untenable, and that we must instead say that properties bestow dispositions. I explore what it is for a property to have such a role essentially. Dispositional essentialists argue for their view by citing certain epistemological and metaphysical implications, and I appeal to these implications to place desiderata on the concept of essence involved. I argue that the traditional modal theory of essence meets these desiderata, but that the resulting theory wrongly implies that certain dispositions essential to mass are essential to charge, thereby offering a new argument against modal theories of essence. I argue that dispositional essentialism requires a primitive notion of essence, and develop a primitivist theory based on Kit Fine's views. I show that the primitivist theory has all the virtues of the modal alternative, and none of the vices. I develop a novel way of thinking about the relationship between properties, laws and dispositions, and argue that it has distinct advantages over standard dispositional essentialist formulations.

Central to the debate between Humean and anti-Humean metaphysics is the question of whether dispositions can exist in the absence of categorical properties that ground them (that is, where the causal burden is shifted on to categorical properties on which the dispositions would therefore supervene). Dispositional essentialists claim that they can; categoricalists reject the possibility of such 'baseless' dispositions, requiring that all dispositions must ultimately have categorical bases. One popular argument, recently dubbed the 'Argument from Science', has appeared in one or another form over much of the last century and purports to win the day for the dispositional essentialist. Taking its cue from physical theory, the Argument from Science treats the exclusively dispositional characterizations of the fundamental particles one finds in physical theory as providing a key premise in what has been called a 'decisive' argument for baseless dispositions. Despite sharing the intuition that dispositions can be baseless, I argue that the force and significance of the Argument from Science have been greatly overestimated: no version of the argument is close to decisive, and only one version succeeds in scoring points against the categoricalist. Not only is physical theory more ontologically innocent than defenders of baseless dispositions seem to appreciate, most versions of the Argument from Science neglect important ways that dispositions could be grounded by categorical properties.