Over the last decade or so, there has been a renewed interest in a view about properties known as quidditism. However, a review of the literature reveals that ‘quidditism’ is used to cover a range of distinct views. In this paper I explore the logical space of distinct types of quidditism. The first distinction noted is between quidditism as a thesis explicitly about property individuation and quidditism as a principle of unrestricted property recombination. The distinction (...) recently drawn by Dustin Locke between extravagant quidditism and austere quidditism is a distinction between quidditisms of the first type. It is then argued that austere quidditism may itself be further sub-divided into what I call ‘extremely austere quidditism’ and ‘moderately austere quidditism’. Moderately austere quidditism is argued to be preferable to extremely austere quidditism and further to be able to address many of the arguments leveled against quidditism in general. (shrink)

Structuralism and quidditism are competing views of the metaphysics of property individuation: structuralists claim that properties are individuated by their nomological roles; quidditists claim that they are individuated by something else. This paper (1) refutes what many see as the best reason to accept structuralism over quidditism and (2) offers a methodological argument in favor of a quidditism. The standard charge against quidditism is that it commits us to something ontologically otiose: intrinsic aspects of properties, so-called (...) ‘quiddities’. Here I grant that quiddities are ontologically otiose, but deny that quidditism requires them. According to a view I call ‘austere quidditism’, properties are individuated by bare numerical identity. I argue that, as far as ontological parsimony is concerned, austere quidditism and structuralism are on a par. But is austere quidditism a coherent alternative to structuralism? To see that it is, we must get clear on what exactly we mean by ‘property individuation’. What we discover is that structuralism is a counterpart theory for properties, and that austere quidditism is simply the rejection of counterpart theory. I conclude with a methodological argument to the effect that counterpart theory for properties ought to be rejected. This paper begins by situating the debate between structuralists and quidditists within the context of a debate over the epistemic limits of fundamental science. At the center of this debate is David Lewis’s posthumously published ‘Ramseyan Humility’ (2008). In the appendix I explain the precise role of austere quidditism in Lewis’s argument. (shrink)

It is widely agreed that properties play causal roles: they capture the causal powers of things. But do properties have their causal roles essentially? David Lewis did not think so. He adhered to the doctrine of quidditism, namely the doctrine that the identity of properties is primitive and that they can trade their causal roles. Quidditism is controversial. But Lewis did not see why he should want to reject it. He knew that he could avoid quidditism on (...) the cheap by treating individuals and properties alike in rejecting transworld multilocation of properties and endorsing a counterpart theory for properties. But he did not see why he should want to do so. In this article, I argue that Lewis should have wanted to endorse a counterpart theory for properties in order to reject quidditism. My argument concerns resemblance relations among properties. Another constitutive role of properties is that they capture objective resemblances between their instances. The premises of my argument are intuitive claims about resemblances among some properties that Lewis held on Humean grounds. (shrink)

In ‘Ramseyan Humility’ Lewis presents the Permutation Argument for quidditism. As he presents it the argument is simple enough, but once one digs beneath its surface, and attempts to understand it in strictly Lewisian terms, difficulties arise. The fundamental difficulty is that, as he presents it, the argument only seems to be sound if one rejects views that Lewis explicitly holds. One aim of this paper is to clarify the argument to show that one can make sense of it (...) in strictly Lewisian terms. In so doing I clarify Lewis’s view, clearly lay out the commitments that Lewis has, and define quidditism in strictly Lewisian terms. However, I also have a secondary aim. Lewis accepts that quidditism entails a form of scepticism, that he calls ‘Humility’. However, by an extension of the permutation argument I show that quidditism entails a form of scepticism, that I call ‘Diffidence’, that is far more wide-reaching than Humility. (shrink)

According to structuralism, all natural properties are individuated by their roles in causal/nomological structures. According to quidditism, at least some natural properties are individuated in some other way. Because these theses deal with the identities of natural properties, this distinction cuts to the core of a serious metaphysical dispute: Are the intrinsic natures of all natural properties essentially causal/nomological in character? I'll argue that the answer is ‘no’, or at least that this answer is more plausible than many critics (...) of quidditism have recognized. In section 1, I distinguish between two versions of quidditism. Bare quidditism holds that worlds with distinct properties and isomorphic structures must be qualitatively identical in the following sense: inhabiting one world would be indistinguishable from inhabiting the other. In contrast, qualitative quidditism allows such worlds to have qualitative differences. In section 2, I discuss an epistemological position that allows us to bett... (shrink)

According to contingentism, laws of nature hold contingently. An objection to contingentism is that it implies quidditism, and therefore inherits its implausible consequences. This paper argues that this objection is misguided. Understood one way, quidditism is not an implication of contingentism, hence even if it has implausible consequences, these are not relevant to contingentism. Understood another way, quidditism is implied by contingentism, but it is less clear if this version of quidditism has the same implausible consequences. (...) Whatever the merits of contingentism, the argument from anti-quidditism is not successful in showing that it is false. (shrink)

In general, properties realize certain roles in the workings of nature. For example, mass makes objects resist acceleration. But what is the relationship between these roles and the properties that realize them? According to ‘quidditism’, the roles are contingently realized by the properties that in fact realize them. Opponents charge that quidditism implies the existence of epiphenomenal and unknowable “quiddities” or “inner natures”. The purpose of this dissertation is to argue in favor of quidditism and explore its (...) epistemic and pragmatic consequences. (shrink)

Aristotle is essentially human; that is, for all possible worlds metaphysically consistent with our own, if Aristotle exists, then he is human. This is a claim about the essential property of an object. The claim that objects have essential properties has been hotly disputed, but for present purposes, we can bracket that issue. In this essay, we are interested, rather, in the question of whether properties themselves have essential properties (or features) for their existence. We call those who suppose they (...) do “property essentialists”; those who do not, “property anti-essentialists,” or “quidditists.” We offer two complementary arguments. Our total argument is under-girded by two assumptions: transworld identity theory and “received view” counterfactual semantics, a la David Lewis. We then argue that, if one presumes that these are true, then one risks running headlong into paradox if one also accepts property anti-essentialism. That's the first argument. By contrast, if one accepts these same assumptions in conjunction with property essentialism, then the paradox is avoided. This is the second argument. We take it that our arguments work to show that, between property essentialism and quidditism, the property essentialist is on better footing. Plausibly, properties themselves do have essential properties for their existence. (shrink)

Properties seem to play an important role in causal relations. But philosophers disagree over whether or not properties play their causal or nomic roles essentially. Causal essentialists say that they do, while quidditists deny it. This article surveys these two views, as well as views that try to find a middle ground.

In this paper, I discuss a connection between quidditism and the Lewisian principle of recombination. I begin by reconstructing a typical characterisation of a Lewisian principle of recombination, followed by an explanation of quidditism. In the remainder, I argue that a proponent of a Lewisian principle of recombination cannot endorse quidditism without some important modifications of her view.

Robert Black argues against quidditism on the grounds that the quidditist is either committed to proper-class many possible worlds and proper-class many possible fundamental properties or must adopt an unacceptably arbitrary restriction on the number of possible fundamental properties. In this paper, I examine Black’s cardinality argument against quidditism and argue that quidditists and non-quidditists alike have reason to reject a key premise of that argument. While it may be the case that the quidditist is committed to nomically (...) indiscernible possible worlds that mark distinctions that make no difference to the physicist, it does not appear that the cardinality of the class of possible worlds or the class of possible fundamental properties postulated by the quidditist is any more problematic than that postulated by the non-quidditist. (shrink)

In ‘Ramseyan Humility’ David Lewis argues that a particular view about fundamental properties, quidditism, leads to the position that we are irredeemably ignorant of the identities of fundamental properties. We are ignorant of the identities of fundamental properties since we can never know which properties play which causal roles, and we have no other way of identifying fundamental properties other than by the causal roles they play. It has been suggested in the philosophical literature that Lewis’ argument for Humility (...) is merely an instance of traditional scepticism, to which traditional responses to scepticism are applicable. I agree that in ‘Ramseyan Humility’ Lewis does present an argument to which it is appropriate to consider the applicability of responses to traditional scepticism—he argues that we irredeemably lack the evidence to rule out possibilities in which different properties occupy the causal roles described by our best physical theory. And prima facie this is just the kind of argument responses to traditional scepticism are designed to tackle. However, I will argue that Lewis bolsters this argument with a second. This second argument serves to deepen Lewis’ case and cannot be met with a response to traditional scepticism. For Lewis argues that not only do we lack evidence for which properties play which roles, we lack the ability to grasp any such proposition about role-occupancy. And if we cannot grasp any such proposition we cannot know it. (shrink)

The paper is a survey of contemporary quidditism, understood as two interrelated metaphysicalpositions — recombinatorial quidditism, which is an account of the nature of possibilities, andindividuation quidditism, which is concerned with the problem of how to individuate properties.I have three aims: to examine the commitments and consequences of both views, to investigatethe relationships between them, and to sketch the logic of the dispute between structuralism andquidditism. I explain how these views relate to Ramseyan humility, according to which (...) we cannotknow the fundamental structure of the world. (shrink)

This chapter argues that we are irremediably ignorant about the identities of the fundamental properties that figure in the actual realization of the true final theory. Of the three published responses to Lewis’s work, each argues that even if Lewis’s metaphysical assumption, the thesis known as “quidditism,” is accepted, we need not accept his epistemic conclusion, the thesis of Humility. The aim of this chapter is to defend Lewis against these critics. Ann Whittle attempts to refute Humility by an (...) appeal to a more lenient account of identification. Following is a defense of Lewis carried by showing that his taxing account of identification is a perfectly good account of at least one perfectly legitimate sense of identification. (shrink)

There is a puzzle concerning the essences of fundamental entities that arises from considerations about essence, on one hand, and fundamentality, on the other. The Essence-Dependence Link (EDL) says that if x figures in the essence of y, then y is dependent upon x. EDL is prima facie plausible in many cases, especially those involving derivative entities. But consider the property negative charge. A negatively charged object exhibits certain behaviors that a positively charged object does not: it moves away from (...) other negatively charged objects, towards positively charged objects, etc. It is commonly thought that negative charge disposes its bearer to move away from other negatively charged objects, towards positively charged objects, etc. But if negative charge is fundamental, then no other entities—including the property positive charge—can figure in its essence. We thus have a prima facie puzzle: How can we say anything interesting about the essences of fundamental entities without running afoul of EDL? In this paper, I present and discuss the consequences of EDL for the debate between causal essentialists and quidditists about properties, and propose solutions to the puzzle. (shrink)

Three basic positions regarding the nature of fundamental properties are: dispositional monism, categorical monism and the mixed view. Dispositional monism apparently involves a regress or circularity, while an unpalatable consequence of categorical monism and the mixed view is that they are committed to quidditism. I discuss Alexander Bird's defence of dispositional monism based on the structuralist approach to identity. I argue that his solution does not help standard dispositional essentialism, as it admits the possibility that two distinct dispositional properties (...) can possess the same stimuli and manifestations. Moreover, Bird's argument can be used to support the mixed view by relieving it of its commitment to quidditism. I briefly analyse an alternative defence of dispositional essentialism based on Leon Horsten's approach to the problem of circularity and impredicativity. I conclude that the best option is to choose Bird's solution but amend the dispositional perspective on properties. According to my proposal, the essences of dispositions are determined not directly by their stimuli and manifestations but by the role each property plays in the structure formed by the stimulus/manifestation relations. (shrink)

In recent literature, it has become clear that quantum physics does not refute Humeanism: Lewis’s thesis of Humean supervenience can be literally true even in the light of quantum entanglement. This point has so far been made with respect to Bohm’s quantum theory. Against this background, this paper seeks to achieve the following four results: to generalize the option of quantum Humeanism from Bohmian mechanics to primitive ontology theories in general; to show that this option applies also to classical mechanics; (...) to establish that it requires a commitment to matter as primitive stuff, but no commitment to natural properties ; to point out that by removing the commitment to properties, the stock metaphysical objections against Humeanism from quidditism and humility no longer apply. In that way, quantum physics strengthens Humeanism instead of refuting it. (shrink)

Causal structuralism is the view that, for each natural, non-mathematical, non-Cambridge property, there is a causal profile that exhausts its individual essence. On this view, having a property’s causal profile is both necessary and sufficient for being that property. It is generally contrasted with the Humean or quidditistic view of properties, which states that having a property’s causal profile is neither necessary nor sufficient for being that property, and with the double-aspect view, which states that causal profile is necessary but (...) not sufficient. Shoemaker’s (1998) and Hawthorne’s (2001) arguments in favor of causal structuralism primarily focus on problematic consequences of the other two views. I argue, however, that causation does not provide an appropriate framework within which to characterize all physical properties for two main reasons. First, there are physical properties that do not have causal profiles and properties whose causal profiles do not exhaust their essences. Second, there is no unified notion of causation across the sciences. After distinguishing between the causal and the nomological, I suggest that what is needed is a structuralist view of properties that is not merely causal but that incorporates a physical property’s higher-order mathematical and nomological properties into its identity conditions. Such a view retains the naturalistic motivations for causal structuralism while avoiding the problems it faces. (shrink)

I develop a metaphysical position that is both lawless and anti-Humean. The position is called realist lawlessness and contrasts with both Humean lawlessness and nomological realism – the claim that there are laws in nature. While the Humean view also allows no laws, realist lawlessness is not Humean because it accepts some necessary connections in nature between distinct properties. Realism about laws, on the other hand, faces a central dilemma. Either laws govern the behaviour of properties from the outside or (...) from the inside. If the former, an unacceptable quidditist view of properties follows. But no plausible account of laws within properties can be developed that permits a governing role specifically for laws. I conclude in favour of eliminativism about laws. At the conceptual core, the notion of a law in nature is misleading. It is suggestive of an otherwise static world in need of animation. (shrink)

Physics presents us with a symphony of natural constants: G, h, c, etc. Up to this point, constants have received comparatively little philosophical attention. In this paper I provide an account of dimensionful constants, in particular the gravitational constant. I propose that they represent inter-quantity structure in the form of relations between quantities with different dimensions. I use this account of G to settle a debate over whether mass scalings are symmetries of Newtonian Gravitation. I argue that they are not, (...) but only if we interpret mass anti-quidditistically. This is analogous to anti-haecceitism in the presence of spacetime symmetries. (shrink)

Those who favour an ontology based on dispositions are thereby able to provide a dispositional essentialist account of the laws of nature. In part 1 of this paper I sketch the dispositional essentialist conception of properties and the concomitant account of laws. In part 2, I characterise various claims about the modal character of properties that fall under the heading ‘quidditism’ and which are consequences of the categoricalist view of properties, which is the alternative to the dispositional essentialist view. (...) I argue that quidditism should be rejected. In part 3, I address a criticism of a strong dispositional essentialist view, viz. that ‘structural’ (i.e. geometrical, numerical, spatial and temporal) properties must be regarded as categorical. (shrink)

A specific variety of formal causation is dispositional essentialism. This chapter argues that dispositional essentialism is incompatible with any trope bundle theory committed to the primitive identity of tropes, such as Keith Campbell’s account and the authors’ own Strong Nuclear Theory. Dispositional essentialism would render at least some tropes identity-dependent on other tropes, while all tropes must be considered identity-independent existents in these trope theories. Furthermore, dispositional essentialism relies on the problematic notion of dispositional essence, and it remains unclear whether (...) dispositional essentialism gains any ontological economy in comparison with the views taking laws of nature as primitive. Finally, the chapter outlines an alternative view based on Deborah Smith’s non-recombinational quidditism. According to it, tropes as determinate particular natures necessarily play certain nomological roles. It is argued that this might be completed with a new conception of tropes as parts of causal processes, which further clarifies the necessary connection between tropes and certain nomological roles. (shrink)

Humeans have a problem with quantities. A core principle of any Humean account of modality is that fundamental entities can freely recombine. But determinate quantities, if fundamental, seem to violate this core principle: determinate quantities belonging to the same determinable necessarily exclude one another. Call this the problem of exclusion. Prominent Humeans have responded in various ways. Wittgenstein, when he resurfaced to philosophy, gave the problem of exclusion as a reason to abandon the logical atomism of the Tractatus with its (...) free recombination of elementary propositions. Armstrong promoted a mereological solution to the problem of exclusion; but his account fails in manifold ways to provide a general solution to the problem. Lewis studiously avoided committing to any one solution, trusting simply that, since Humeanism was true, there had to be some solution. Abandonment; failure; avoidance: we Humeans need to do better. -/- In this paper, I present what I take to be the best account of quantities, tailoring it where needed to meet Humean demands as well as my own prior commitment to quidditism, and my own comparativist inclinations. In short: determinables, not determinates, are the fundamental properties, and freely recombine; determinates arise from the instantiation of determinables in an enhanced world structure; determinate quantities may be local (in a sense to be explained), but they are not intrinsic. Is the account I end up with Humean? Not, unfortunately, as it stands: the problem of exclusion still rears its ugly head. After dismissing a failed attempt at a solution, I consider in the final section the two viable Humean options. One attributes the source of the necessary exclusions to conventional definition, the other attributes it to logic. The first is safe and familiar, but not a response I can accept given my other commitments. The second is more radical and less familiar; but I am convinced it is on the right track. I don’t have space to develop it much here, but I put it out for future research. (shrink)

Metaphysical grounding is often presented as a relation of directed dependence analogous to causation. The relationship between causation, properties, and laws of nature is hotly debated. I ask: what is the relationship between grounding, properties, and laws of metaphysics? I begin by considering the grounding analogue of Humean quidditism. Finding it implausible, I turn to the primitive-laws account of grounding, recently defended by Jonathan Schaffer and others. I argue this view is also unsatisfactory. I then present several possible dispositionalist-like (...) accounts and characterize the notion of a power to ground. I argue for three important conclusions: (i) each property essentially confers grounding powers; (ii) non-fundamental properties can be defined structurally in a particular sense, elucidating the claim that they are ‘nothing over and above’ the fundamental; and (iii) fundamental properties play a central role in grounding the grounding facts. Finally, it is significant that, combined with a causal powers-account of causal explanation, the door is open to a unified account of the metaphysics of causation and grounding: both flow from the natures of fundamental properties. (shrink)

This is a discussion of some themes in Max Tegmark’s recent book, Our Mathematical Universe. It was written as a review for Plus Magazine, the online magazine of the UK’s national mathematics education and outreach project, the Mathematics Millennium Project. Since some of the discussion---about symmetry breaking, and Pythagoreanism in the philosophy of mathematics---went beyond reviewing Tegmark’s book, the material was divided into three online articles. This version combines those three articles, and adds some other material, in particular a brief (...) defence of quidditism about properties. It also adds some references, to other Plus articles as well as academic articles. But it retains the informal style of Plus. (shrink)

In the recent debate about the nature of properties, dispositional essentialism, which claims that a property possesses its powers essentially, seems to provide an interesting alternative to the quite simple and problematic view that properties are to be identified through primitive qualities, quidditates. However, it is not easy to characterize explicitly and uncontroversially dispositional essentialism, in particular when it comes to the treatment of powers. A further reference to primitive qualities may prove to be unavoidable, thus suggesting a medium between (...) quidditism and dispositional essentialism. Whatever means are used in the explanation of a property’s nature, the resort to a rock-bottom entity like a quidditas seems to be the only way to avoid a regress. (shrink)

The paper has three parts. In the first part ExtOSR, an extended version of Ontic Structural Realism, will be introduced. ExtOSR considers structural properties as ontological primitives, where structural properties are understood as comprising both relational and structurally derived intrinsic properties or structure invariants. It is argued that ExtOSR is best suited to accommodate gauge symmetry invariants and zero value properties. In the second part, ExtOSR will be given a Humean shape by considering structures as categorical and global. It will (...) be laid out how such structures serve to reconstruct non-essential structural kinds and laws. In the third part Humean structural realism will be defended against the threat of quidditism. (shrink)

This thesis concerns the relation between the fundamental properties and the powers they confer. The views considered are introduced in terms of their acceptance or rejection of the quiddistic thesis. Essentially the quiddistic thesis claims that properties confer the powers they do neither necessarily nor sufficiently. Quidditism is the view that accepts the quiddistic thesis. The other two views to be considered, the pure powers view and the grounded view reject the quiddistic thesis. The pure powers view supports its (...) denial of the quiddistic thesis with the claim that properties consist in conferring the powers they do; the possession of a property just is the possession of a power. The grounded view, the positive view of this thesis, rejects the idea that properties are constituted by conferring the causal powers they do. Rather on the grounded view, it is the natures of the fundamental properties that metaphysically explain why they confer the powers they do. (shrink)

Ramseyan humility is the thesis that we cannot know which properties realize the roles specified by the laws of completed physics. Lewis seems to offer a sceptical argument for this conclusion. Humean fundamental properties can be permuted as to their causal roles and distribution throughout spacetime, yielding alternative possible worlds with the same fundamental structure as actuality, but at which the totality of available evidence is the same. On the assumption that empirical knowledge requires evidence, we cannot know which of (...) these worlds is actual. However, Lewis also appeals to a range of familiar semantic principles when framing his argument, which leads some authors to suppose that he can also plausibly be interpreted as offering a purely semantic argument for humility in addition. In this paper I grant that these arguments are Lewisian, but argue that Lewis is also committed to a theory of mind that licenses a purely metaphysical argument for humility based on the idea that mental properties supervene on fundamental structure. Given that knowing which x is the F requires knowing that a is the F, the supposition that we could come to know which properties actually occupy the fundamental roles entails differences in mental properties between worlds with the same fundamental structure, violating supervenience. Humility follows right away, without any further epistemic or semantic principles. This argument is immune to almost every way of rebutting the sceptical and semantic arguments; conversely, almost every way of rebutting the metaphysical argument tells equally against the others. (shrink)

Some properties such as having a beard and being a philosopher are intuitively qualitative, while other properties such as being identical to Plato and being a student of Socrates are intuitively non-qualitative. It is often assumed that, necessarily, a property is qualitative if and only if it can be designated descriptively without the aid of directly referential devices. I argue that this linguistic thesis fails in both directions: there might be non-qualitative properties that can be designated descriptively, and there appear (...) to be qualitative properties that can only be designated directly. I conclude that while the linguistic thesis is ultimately untenable as stated, it can be plausibly recast as a thesis about our concepts rather than the properties they designate. (shrink)

David Lewis has argued that we cannot identify the fundamental properties. It is generally accepted that we can resist Lewis's conclusion if we are prepared to accept a structuralist account of fundamental properties, according to which their causal/nomological role is essential to their identity. I argue, to the contrary, that a structuralist construal of fundamental properties does not sustain a successful independent strategy for resisting Lewis's conclusion. The structuralist can vindicate our ability to identify fundamental properties only if she accepts (...) epistemic principles that suffice for blocking Lewis's conclusion even if fundamental properties are not construed along structuralist lines. (shrink)

Jonathan Schaffer argues against a necessary connection between properties and laws. He takes this to be a question of what possible worlds we ought to countenance in our best theories of modality, counterfactuals, etc. In doing so, he unfairly rigs the game in favor of contingentism. I argue that the necessitarian can resist Schaffer’s conclusion while accepting his key premise that our best theories of modality, counterfactuals, etc. require a very wide range of things called ‘possible worlds’. However, the necessitarian (...) can and should insist that, in many cases, these worlds are not metaphysically possible. I will further argue that, having taken such a stance, the necessitarian has additional resources to respond to Schaffer’s other arguments against the view. (shrink)