Online research in philosophy

In Mumford’s Dispositions, the reader will find an extended treatment of the recent debate about dispositions from Ryle and Geach to the present. Along the way, Mumford presents his own views on several key points, though we found the book much more thorough in its assessment of opposing views than in the development of a positive account. As we’ll try to make clear, some of the ideas endorsed in Dispositions are certainly worth pursuing; others are not. Following Mackie, Shoemaker, and others,1 Mumford stresses that it’s one thing to distinguish between dispositional and categorical ascriptions and quite another to draw an ontological line between dispositional and categorical properties. The book itself can be divided roughly into those chapters that deal with the relationship between dispositional ascriptions and corresponding conditionals (like ‘is fragile’ and ‘would break if struck’); and those chapters that deal with the relationship between dispositions and their categorical bases (like fragility and having internal structure XYZ). We shall examine each cluster of issues in turn.

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.

Reductionists about dispositions must either say the natural properties are all dispositional or individuate properties hyperintensionally. Lewis stands in as an example of the sort of combination I think is incoherent: properties individuated by modal profile + categoricalism.

This essay defends a theory of dispositions, on which dispositional properties are analyzable in terms of agents’ abilities. On this view, claims about dispositions are a projection of agent-centric facts about manipulability onto a world whose nature, considered in itself, is exhausted by the categorical.

I will argue firstly that law-statements should be understood as attributing dispositional properties. Second, the dispositions I am talking about should not be conceived as causes of their manifestations but rather as contributors to the behavior of compound systems. And finally I will defend the claim that dispositional properties cannot be reduced in any straightforward sense to non-dispositional (categorical) properties and that they need no categorical bases in the first place.

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.

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.

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.

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.

Several prominent philosophers have held that physical properties are dispositions. The aim of this paper is to establish the following conjunction: if the thesis that physical properties are dispositions is unsupplemented by controversial assumptions about dispositions, it entails a contradiction; and if it is so supplemented the resulting theory has the consequence that either many worlds which seem to be possible worlds are not possible worlds or some properties which seem to be identical are not identical. In this way it is shown that a dispositional account of physical properties is implausible.