In the last 35 years many philosophers have appealed to reference magnetism to explain how it is that we mean what we mean. The idea is that it is a constitutive principle of metasemantics that the interpretation that assigns the more natural meanings is correct, _ceteris paribus_. Among other things, magnetism has been used to answer the challenges of grue and quus, Quine’s indeterminacy of translation argument, and Putnam’s model-theoretic argument against realism. Critics of magnetism have usually objected to the (...) base notion of naturalness. Here I assume naturalness for the sake of argument, but argue that even still, reference magnetism should be rejected. The supposed force of reference magnetism is arbitrarily weak, and the best explanation of this is that it simply does not exist. (shrink)

We can use radically different reference‐schemes to generate the same truth‐conditions for the sentences of a language. In this paper, we do three things. (1) Distinguish two arguments that deploy this observation to derive different conclusions. The first argues that reference is radically indeterminate: there is no fact of the matter what ordinary terms refer to. This threat is taken seriously and most contemporary metasemantic theories come with resources intended to rebut it. The second argues for radical parochialism about reference: (...) it's a reflection of our parochial interests, rather than the nature of the subject matter, that our theorizing about language appeals to reference rather than another relation that generates the same truth‐conditions. Rebuttals of the first argument cut no ice against the second, because radical parochialism is compatible with reference being determinate. (2) Argue that radical parochialism, like radical indeterminacy, would be shocking if true. (3) Argue that the case for radical parochialism turns on the explanatory purposes of “reference”‐talk: on relatively “thin” conceptions, the argument goes through, and radical parochialism is (shockingly!) true; on richer conceptions, the argument can be blocked. We conclude that non‐revisionists must endorse, and justify, a relatively rich conception of the explanatory purposes of “reference”‐talk. (shrink)

This paper begins with a puzzle regarding Lewis' theory of radical interpretation. On the one hand, Lewis convincingly argued that the facts about an agent's sensory evidence and choices will always underdetermine the facts about her beliefs and desires. On the other hand, we have several representation theorems—such as those of (Ramsey 1931) and (Savage 1954)—that are widely taken to show that if an agent's choices satisfy certain constraints, then those choices can suffice to determine her beliefs and desires. In (...) this paper, I will argue that Lewis' conclusion is correct: choices radically underdetermine beliefs and desires, and representation theorems provide us with no good reasons to think otherwise. Any tension with those theorems is merely apparent, and relates ultimately to the difference between how 'choices' are understood within Lewis' theory and the problematic way that they're represented in the context of the representation theorems. For the purposes of radical interpretation, representation theorems like Ramsey's and Savage's just aren't very relevant after all. (shrink)

David Lewis’s arguments against magical ersatzism are notoriously puzzling. Untangling different strands in those arguments is useful for bringing out what he thought was wrong with not just one style of theory about possible worlds, but with much of the contemporary metaphysics of abstract objects. After setting out what I take Lewis’s arguments to be and how best to resist them, I consider the application of those arguments to general theories of properties and relations. The constraints Lewis motivates turn out (...) to yield an argument for concretism about possible individuals that is quite different from the better-known Lewisian arguments for that position. The discussion also touches on the puzzling question of whether things are the way they are because of the properties they have, or are the properties and relations the way they are because of the things that have them. (shrink)

Possible worlds models of belief have difficulties accounting for unawareness, the inability to entertain (and hence believe) certain propositions. Accommodating unawareness is important for adequately modelling epistemic states, and representing the informational content to which agents have in principle access given their explicit beliefs. In this paper, I develop a model of explicit belief, awareness, and informational content, along with an sound and complete axiomatisation. I furthermore defend the model against the seminal impossibility result of Dekel, Lipman and Rustichini, according (...) to which three intuitive conditions preclude non-trivial unawareness on any possible worlds model of belief. (shrink)

This paper attempts to revive a once-lively program in the philosophy of language—that of reducing linguistic phenomena to facts about mental states and actions. I argue that recent skepticism toward this project is generated by features of traditional implementations of the project, rather than the project itself. A picture of language as essentially a mechanism for cooperative information exchange attracted theorists to metasemantic accounts grounding language use in illocutionary action (roughly, using an utterance to elicit a propositional attitude). When this (...) picture is rejected, a metasemantics grounding language in locutionary action (using an utterance to direct attention) emerges as a more viable proposal, dissolving an intractable issue for traditional theories: The metasemantics of subsentential expressions. (shrink)

Many epistemological problems can be solved by the objective Bayesian view that there are rationality constraints on priors, that is, inductive probabilities. But attempts to work out these constraints have run into such serious problems that many have rejected objective Bayesianism altogether. I argue that the epistemologist should borrow the metaphysician’s concept of naturalness and assign higher priors to more natural hypotheses.

In the paper I defend the idea of metametasemantics against the arguments recently presented by Ori Simchen. Simchen attacks the view, according to which metametasemantics incorporating all possible metasemantic accounts is necessary to protect the metasemantic theories from the notorious problem of inscrutability of reference. Simchen claims that if metametasemantics is allowed it ‘absorbs’ metasemantic theories to the extent that it diminishes their explanatory value. Furthermore, in this way Simchen sets up two main metasemantic paradigms i.e. productivism and interpretationism as (...) the rival theories inevitably excluding each other. I endeavour to undermine Simchen’s point by demonstrating that his argumentation mixes up deflationary reading of the predicate ‘is true’ with its substantial reading. Consequently, I demonstrate that accepting metametasemantics does not diminish explanatory value of various metasemantic theories and thus that there is no good reason to forbid metametasemantics. I also argue that even if we ignore the above-mentioned confusion in Simchen’s reasoning, his arguments still fail when considering various problems with the notion of diminishment of explanatory value and because the analogy that his arguments are based on is fairly weak. Eventually, I conclude that metametasemantics does not pose any danger to metasemantics and that it provides a solid ground for developing a theory that benefits from both productivism and interpretationism. (shrink)

In this paper, I discuss a specific approach to measuring and comparing the simplicity of theories that is based on Lewis’s notion of fundamental properties. In particular, I discuss the criterion of simplicity as stated by Williams. According to Williams, the best candidate for a theory is the one which has the shortest definition in terms of fundamental properties. The aim of this paper is to show that the criterion thus specified has two constraints. First, the criterion is not applicable (...) to cases in which candidates for theories that specify fundamental properties are compared. Secondly, the applicability of the criterion in social sciences seems to be unwarranted. (shrink)

In ‘Putnam’s Paradox’, Lewis defended global descriptivism and reference magnetism. According to Schwarz [2014], Lewis didn’t mean what he said there, and really held neither position. We present evidence from Lewis’s correspondence and publications which shows conclusively that Lewis endorsed both.

Divers (2014) argues that a Lewisian theory of modality which includes both counterpart theory and modal realism cannot account for the truth of certain intuitively true modal sentences involving cross-world comparatives. The main purpose of this paper is to defend the Lewisian theory against Divers’s challenge by developing a response strategy based on a degree-theoretic treatment of comparatives and by showing that this treatment is compatible with the theory.

First-order normative theories concerning what’s right and wrong, good and bad, etc. and metanormative theories concerning the nature of first-order normative thought and talk are widely regarded as independent theoretical enterprises. This paper argues that several debates in metanormative theory involve views that have first-order normative implications, even as the implications in question may not be immediately recognizable as normative. I first make my claim more precise by outlining a general recipe for generating this result. I then apply this recipe (...) to three debates in metaethics: the modal status of basic normative principles, normative vagueness and indeterminacy, and the determination of reference for normative predicates. In each case I argue that certain views on each issue carry first-order normative commitments, in accordance with my recipe. (shrink)

According to the standard interpretation of Lewis’s theory of predicate meaning (the U&N theory), the naturalness of meaning candidates should be stated metaphysically - as a length of definition in terms of fundamental properties. Recently, Weatherson has criticized the U&N theory and argued that the criterion of naturalness should be stated epistemologically - as the amount of evidence needed to form a belief. Despite the criticism, his attitude towards the U&N theory is quite relaxed. According to Weatherson, the U&N theory (...) can be used as a good heuristic for delivering the correct verdicts when doing applied semantics, i.e., when we try to determine the best meaning candidate for a particular predicate. In this paper, I try to show that the “good heuristic strategy” is of no use because A) there is no guarantee that the epistemological and the metaphysical criteria of naturalness deliver the same verdicts and B) even if they deliver the same verdicts, the difference in their theoretical backgrounds may affect arguments which rely on the verdicts. The difference will be shown by drawing on the example of Theodore Sider and his use of the U&N theory. (shrink)

ABSTRACT: A traditional objection to inferentialism states that not all inferences can be meaning-constitutive and therefore inferentialism has to comprise an analytic-synthetic distinction. As a response, Peregrin argues that meaning is a matter of inferential rules and only the subset of all the valid inferences for which there is a widely shared corrective behaviour corresponds to rules and so determines meaning. Unfortunately, Peregrin does not discuss what counts as “widely shared”. In the paper, I argue for an empirical plausibility of (...) Peregrin’s proposal. The aim of the paper is to show that we can find examples of meaning-constitutive linguistic action, which sustain Peregrin’s response. The idea is supported by examples of meaning modulation. If Peregrin is right, then we should be able to find specific meaning modulations in which a new meaning is publicly available and modulated in such a way that it has a potential to be widely shared. I believe that binding modulations – a specific type of meaning modulations – satisfy this condition. (shrink)

The concept of moral wrongness, many think, has a distinctive kind of referential stability, brought out by moral twin earth cases. This article offers a new account of the source of this stability, deriving it from a metaphysics of content: “substantive” radical interpretation, and first-order normative assumptions. This story is distinguished from extant “reference magnetic” explanations of the phenomenon, and objections and replies are considered.

The general thesis of this paper is that metasemantic theories can play a central role in determining the correct solution to the liar paradox. I argue for the thesis by providing a specific example. I show how Lewis’s reference-magnetic metasemantic theory may decide between two of the most influential solutions to the liar paradox: Kripke’s minimal fixed point theory of truth and Gupta and Belnap’s revision theory of truth. In particular, I suggest that Lewis’s metasemantic theory favours Kripke’s solution to (...) the paradox over Gupta and Belnap’s. I then sketch how other standard criteria for assessing solutions to the liar paradox, such as whether a solution faces a so-called revenge paradox, fit into this picture. While the discussion of the specific example is itself important, the underlying lesson is that we have an unused strategy for resolving one of the hardest problems in philosophy. (shrink)

Metaethical realists disagree about the nature of normative properties. Naturalists think that they are ordinary natural properties: causally efficacious, a posteriori knowable, and usable in the best explanations of natural and social sciences. Non-naturalist realists, in contrast, argue that they are sui generis: causally inert, a priori knowable and not a part of the subject matter of sciences. It has been assumed so far that naturalists can explain causally how the normative predicates manage to refer to normative properties, whereas non-naturalists (...) are unable to provide equally satisfactory metasemantic explanations. This article first describes how the previous non-naturalist accounts of reference fail to tell us how the normative predicates could have come to refer to the non-natural properties rather than to the natural ones. I will then use the so-called qua-problem to show how the causal theories of reference of naturalists also fail to fix the reference of normative predicates to unique natural properties. Finally, I will suggest that, just as naturalists need to rely on the non-causal mechanism of reference magnetism to solve the previous problem, non-naturalists, too, can rely on the very same idea to respond to the pressing metasemantic challenges that they face concerning reference. (shrink)

The main question of this paper is: how do we manage to know what our own degrees of belief are? Section 1 briefly reviews and criticizes the traditional functionalist view, a view notably associated with David Lewis and sometimes called the theory-theory. I use this criticism to motivate the approach I want to promote. Section 2, the bulk of the paper, examines and begins to develop the view that we have a special kind of introspective access to our degrees of (...) belief. I give an initial assessment of the view by examining its compatibility with leading theories of introspection. And I identify a challenge for the view, and explain why I'm optimistic that the view can overcome it. (shrink)

The Problem of Overlappers is a puzzle about what makes it the case, and how we can know, that we have the parts we intuitively think we have. In this paper, I develop and motivate an overlooked solution to this puzzle. According to what I call the self-making view it is within our power to decide what we refer to with the personal pronoun ‘I’, so the truth of most of our beliefs about our parts is ensured by the very (...) mechanism of self-reference. Other than providing an elegant solution to the Problem of Overlappers, the view can be motivated on independent grounds. It also has wide-ranging consequences for how we should be thinking about persons. Among other things, it can help undermine an influential line of argument against the permissibility of elective amputation. After a detailed discussion and defence of the self-making view, I consider some objections to it. I conclude that none of these objections is persuasive and we should at the very least take seriously the idea that we are to some extent self-made. (shrink)

The principle of mass additivity states that the mass of a composite object is the sum of the masses of its elementary components. Mass additivity is true in Newtonian mechanics but false in special relativity. Physicists have explained why mass additivity is true in Newtonian mechanics by reducing it to Newton’s microphysical laws. This reductive explanation does not fit well with deducibility theories of reductive explanation such as the modern Nagelian theory of reduction, and the a priori entailment theory of (...) reduction that is prominent in the philosophy of mind. Nonetheless, I argue that a reconstruction of the explanation that incorporates distinctively philosophical concepts in fact fits both theories. I discuss the implications of this result for both theories and for the reductive explanation of consciousness. (shrink)

David Lewis famously argued that the time traveller ‘can’ murder her grandfather, even though she never will: it is compossible with a particular set of facts including her motive, opportunity and skill . I argue that while ordinary agents ‘can’ under Lewis’s conception, philosophers cannot – the latter will not only fail to fulfill their homicidal intentions but also fail to form them in the first place.

If someone disagrees with my moral views, or more generally if I’m in a group of n people who all disagree with each other, but I don’t have any special evidence or basis for my epistemic superiority, then it’s at best a 1-in-n chance that my views are correct. The skeptical threat from disagreement is thus a kind of moral lottery, to adapt a similar metaphor from Sharon Street. Her own genealogical debunking argument, as I discuss, relies on a premise (...) of such disagreement among evolutionary counterparts. -/- In this paper, I resist the threat from disagreement by showing that, on some of the most influential and most attractive theories of content determination, the premise of moral disagreement cannot serve any skeptical or revisionary purposes. I examine and criticize attempts, made by Gilbert Harman and Sharon Street, to argue from disagreement to relativism by relying on a theory of content determination that involves a principle that, within certain constraints, maximizes the attribution to us of true beliefs. And I examine and criticize Robert Williams’s attempt to show there is moral disagreement by relying on a theory of content determination that involves a principle that instead maximizes the attribution to us of rationality. My overall aim is to defend commonsense moral realism via a careful look at the theory of content and concepts. (shrink)

In this article, I argue that if tacit knowledge of grammar is analyzable in functional‐computational terms, then it cannot ground linguistic meaning, structure, or sound. If to know or cognize a grammar is to be in a certain computational state playing a certain functional role, there can be no unique grammar cognized. Satisfying the functional conditions for cognizing a grammar G entails satisfying those for cognizing many grammars disagreeing with G about expressions' semantic, phonetic, and syntactic values. This threatens the (...) Chomskyan view that expressions have such values for speakers because they cognize grammars assigning them those values. For if this is true, semantics, syntax, and phonology must be indeterminate, thanks to the indeterminacy of grammar‐cognizing (qua functional‐computational state). So, the fact that a speaker cognizes a grammar cannot explain the determinate character of their language. (shrink)

How is grounding related to metaphysical explanation? The standard view is that the former somehow “backs”, “undergirds” or “underlies” the latter. This view fits into a general picture of explanation, according to which explanations in general hold in virtue of a certain elite group of “explanatory relations” or “determinative relations” that back them. This paper turns the standard view on its head: grounding doesn't “back” metaphysical explanation but is in an important sense downstream from it. I call this view “grounding (...) idealism”, since it structurally resembles an analogous view about causation that is known as “causal idealism” and has been endorsed by philosophers like Michael Scriven and Philip Kitcher. I formulate a specific version of grounding idealism, Metaphysical Explanation‐First Idealism (MEFI), according to which the semantic value of ‘grounding’ is an abundant, gerrymandered relation settled by the metaphysical explanation facts. Then I offer some theoretical considerations that support MEFI over rival accounts of the relation between grounding and metaphysical explanation. Finally, I address the question of what role is left for grounding to play, if not that of “backing” metaphysical explanations. (shrink)

Much recent metaphysics is built around notions such as naturalness, fundamentality, grounding, dependence, essence, and others besides. In this article I raise a problem for this kind of metaphysics, the “problem of missing value.” I survey a number of possible solutions to the problem and find them all wanting. This suggests a return to a kind of Goodmanian view that the world is a structureless mess onto which we project our own categorizations, not something with categories already built in.

In this dissertation, I defend a Russellian form of descriptivism. The main supporting argument invokes a relation between meaning and thought. I argue that the meanings of sentences are the thoughts people use them to express. This is part of a Gricean outlook on meaning according to which psychological intentionality is prior to, and determinative of, linguistic intentionality. The right approach to thought, I argue in Chapter 1, is a type of functionalism on which thoughts have narrow contents. On this (...) view, the attitude ascriptions of a regimented psychology capture what people really believe and desire. These attitude ascriptions have content clauses that are what David Lewis calls ‘modified Ramsey sentences.’ I then conclude that, since the meanings of sentences are the narrow contents of the thoughts speakers use them to express, the meanings of sentences can also be represented with such descriptive sentences. I extend the view so that it applies to individual words. The resulting view is a form of descriptivism. Referring, I claim in Chapter 2, is the expression of a de re attitude. I argue that the non-psychological, de re individuation of thoughts captures only contingent features of these thoughts. Furthermore, whether a thought counts as de re depends on the attributor’s context. These two characteristics carry over to reference. The referential properties of speech acts and expressions are merely contingent features. Furthermore, whether a speech act or expression counts as referring depends upon the attributor’s context. In Chapter 3, I apply this version of descriptivism to indexicals, demonstratives and names. Indexicals turn out to have non-descriptive, context-insensitive, semantically determined meanings. Demonstratives have descriptive, context-sensitive, pragmatically determined meanings. Names, finally, have descriptive, context-insensitive, semantically determined meanings. In the final chapter, I address Putnam's model-theoretic argument, the most formidable obstacle to the form descriptivism outlined here. I criticize Lewis's ‘magnetist’ solution that invokes primitive naturalness because it is committed to the existence of incorrigible error about the external world. I suggest an empiricist approach on which psychological intentionality, and so ultimately linguistic intentionality as well, is anchored in experience. (shrink)

This article suggests that Chomsky’s notorious ‘London’ argument against semantics looks much more plausible that it is usually interpreted as being when seen in the light of something apparently remote from its concerns, viz., David Lewis’s distinction between natural and non-natural properties.

The criterion of naturalness represents David Lewis’s attempt to answer some of the sceptical arguments in semantics by comparing the naturalness of meaning candidates. Recently, the criterion has been challenged by a new sceptical argument. Williams argues that the criterion cannot rule out the candidates which are not permuted versions of an intended interpretation. He presents such a candidate – the arithmetical interpretation semantics by comparing the naturalness of meaning candidates. Recently, the criterion has been challenged by a new sceptical (...) argument. Williams argues that the criterion cannot rule out the candidates which are not permuted versions of an intended interpretation. He presents such a candidate – the arithmetical interpretation, and he argues that it opens up the possibility of Pythagorean worlds, i.e. the worlds similar to ours in which the arithmetical interpretation is the best candidate for a semantic theory. The aim of this paper is a) to reconsider the general conditions for the applicability of Lewis’s criterion of naturalness and b) to show that Williams’s new sceptical challenge is based on a problematic assumption that the arithmetical interpretation is independent of fundamental properties and relations. As I show, if the criterion of naturalness is applied properly, it can respond even to the new sceptical challenge. (shrink)

Metaphysicians now typically distinguish between a theory’s ontology and its ideology. But besides a few cursory efforts, no one has explained the role of ideology in theory choice. In this paper I develop a framework for discussing how differing approaches to ideology impact metaphysical disputes. I first provide an initial characterization of ideology and develop two contrasting types of criteria used to evaluate its quality. In using externalist criteria, we judge the quality of a theory’s ideology by its relation to (...) external features of the world. In contrast, in using internalist criteria, we judge the quality of a theory’s ideology by features internal to the theory and the theorizer, e.g. the intelligibility of the terminology employed. I then argue for an unrestricted application of externalist criteria, what I call maximal realism. According to maximal realism, we ought to apply externalist criteria to the entirety of a theory’s ideology—to not only predicates but also to quantifiers and logical operators. I defend maximal realism from what I take to be the best objection to it: that the view leads to bad questions. As part of my defense, I argue that those who would restrict their application of externalist criteria either adopt an unjustified partition of ideology or reject seemingly benign questions. Finally, I apply my discussion of ideology to two extant metaphysical disputes. (shrink)

I consider two competing approaches to metasemantics: productivism, whereby endowment with semantic significance emerges directly from conditions surrounding the production or employment of the items semantically endowed; and interpretationism, whereby endowment with semantic significance emerges directly from conditions surrounding the interpretive consumption of such items. Focusing on the version of interpretationism developed by Lewis and his followers, I present a novel argument to the conclusion that such an approach cannot secure determinacy for singular reference. I then draw a larger moral (...) for metasemantics and its relation to truth-conditional semantics. (shrink)

The project of this chapter is to explore some relations between the rule-following considerations and radical interpretation. I spell out the sense in which the rule-following considerations are about meaning determination, and investigate whether the principle of meaning determination used in the early Davidson's account of meaning determination - the principle of charity - provides an answer to what I shall call "Wittgenstein's paradox". More precisely, I am interested in one aspect of the paradox: the "problem of objectivity". My question (...) then is whether meaning, as determined by charity, is such that the correctness of the applications of meaningful expressions is an objective matter. After running us through the basics of the radical interpretation account of meaning determination I argue that the principle of charity does seem to fall prey to the problem of objectivity. After unsuccessfully trying to rescue objectivity by means of Lewisian natural properties, this is the verdict I in the end endorse. (shrink)

This thesis investigates the metaphysical nature of necessity. My study focuses primarily on the reduction of metaphysical necessity and the question of whether a necessary truth can be reductively defined. Theodore Sider develops a new reductive account of metaphysical necessity. Unfortunately, the multiple realizability problem posed by Jonathan Schaffer undermines the credibility of Sider’s account. This underlies my motivation to search for a revised Siderian account of necessity. On this basis, I propose a modified version of Sider’s account and argue (...) that analytic, natural-kind and micro-reduction truths are necessary truths if and only if they express the same states of affairs as logical truths. Since logical truths are necessary truths, analytic, natural-kind and micro-reduction truths are necessary truths as well. In this thesis, I will proceed as follows. Chapter 1 introduces Sider’s account of necessity. In particular, I focus on his analysis of the necessity of a micro-reduction truth. His analysis is largely constitutive of the notion of a metaphysical semantics and some associated notions. I reconstruct his analysis and articulate his metaphysical semantics and the associated notions. Chapter 2 presents and clarifies the multiple realizability problem of Schaffer. His critique shows that Sider’s metaphysical semantics cannot handle multiple realizability. Sider refutes this claim by arguing that the multiple realizability problem is a problem for his analysis of the necessity of a micro-reduction truth, not for his metaphysical semantics itself. This is a good starting point to propound a modified account of necessity. Chapter 3 proposes and articulates my modified analysis of the necessity of a micro-reduction, where I show that the necessity of a micro-reduction truth can be reductively defined without appeal to Sider’s metaphysical semantics. I argue that analytic, natural-kind and microreduction truths are necessary truths if and only if they express the same states of affairs as logical truths. Logical truths are necessary and so are they. After that, I consider a potential objection to my modified account and attempt to respond to it. (shrink)

In the International System of Units, ‘meter’ is defined in terms of seconds and the speed of light, and ‘second’ is defined in terms of properties of cesium 133 atoms. I show that one consequence of these definitions is that: if there is a minimal length, then the chances that ‘meter’ is completely determinate are only 1 in 21,413,747. Moreover, we have good reason to believe that there is a minimal length. Thus, it is highly probable that ‘meter’ is indeterminate. (...) If the meter is indeterminate, then any unit in the SI system that is defined in terms of the meter is indeterminate as well. This problem affects most of the familiar derived units in SI. As such, it is highly likely that indeterminacy pervades the SI system. The indeterminacy of the meter is compared and contrasted with emerging literature on indeterminacy in measurement locutions. Moreover, the indeterminacy of the meter has ramifications for the metaphysics of measurement and the semantics of measurement locutions. Finally, it is shown how to redefine ‘meter’ and ‘second’ to completely avoid the indeterminacy. (shrink)

In the International System of Units (SI), ‘meter’ is defined in terms of seconds and the speed of light, and ‘second’ is defined in terms of properties of cesium 133 atoms. I show that one consequence of these definitions is that: if there is a minimal length (e.g., Planck length), then the chances that ‘meter’ is completely determinate are only 1 in 21,413,747. Moreover, we have good reason to believe that there is a minimal length. Thus, it is highly probable (...) that ‘meter’ is indeterminate. If the meter is indeterminate, then any unit in the SI system that is defined in terms of the meter is indeterminate as well. This problem affects most of the familiar derived units in SI. As such, it is highly likely that indeterminacy pervades the SI system. The indeterminacy of the meter is compared and contrasted with emerging literature on indeterminacy in measurement locutions (as in Eran Tal’s recent argument that measurement units are vague in certain ways). Moreover, the indeterminacy of the meter has ramifications for the metaphysics of measurement (e.g., problems for widespread assumptions about the nature of conventionality, as in Theodore Sider’s Writing the Book of the World) and the semantics of measurement locutions (e.g., undermining the received view that measurement phrases are absolutely precise as in Christopher Kennedy’s and Louise McNally’s semantics for gradable adjectives). Finally, it is shown how to redefine ‘meter’ and ‘second’ to completely avoid the indeterminacy. (shrink)

David Lewis (1941–2001) was one of the most important philosophers of the 20th Century. He made significant contributions to philosophy of language, philosophy of mathematics, philosophy of science, decision theory, epistemology, meta-ethics and aesthetics. In most of these fields he is essential reading; in many of them he is among the most important figures of recent decades. And this list leaves out his two most significant contributions. -/- In philosophy of mind, Lewis developed and defended at length a new version (...) of materialism (see the entry on physicalism). He started by showing how the motivations driving the identity theory of mind and functionalism could be reconciled in his theory of mind. He called this an identity theory, though his theory motivated the position now known as analytic functionalism. And he developed detailed accounts of mental content (building on Davidson’s interpretationism) and phenomenal knowledge (building on Nemirow’s ability hypothesis) that are consistent with his materialism. The synthesis Lewis ended up with is one of the central positions in contemporary debates in philosophy of mind. -/- But his largest contributions were in metaphysics. One branch of his metaphysics was his Hume-inspired reductionism about the nomological. He developed a position he called “Humean supervenience”, the theory that said that there was nothing to reality except the spatio-temporal distribution of local natural properties. And he did this by showing in detail how laws, chances, counterfactual dependence, causation, dispositions and colours could be located within this Humean mosaic. The other branch of his metaphysics was his modal realism. Lewis held that the best theory of modality posited concrete possible worlds. A proposition is possible if and only if it is true at one of these worlds. Lewis defended this view in his most significant book, On the Plurality of Worlds. Alongside this, Lewis developed a new account of how to think about modal properties of individuals, namely counterpart theory, and showed how this theory resolved several long-standing puzzles about modal properties. (shrink)