This paper provides an exposition and defence of Lewis' theory of radical interpretation. The first part explains what Lewis' theory was; the second part explains what it wasn't, and in so doing addresses a number of common objections that arise as a result of widespread myths and misunderstandings about how Lewis' theory is supposed to work.

Near the end of 'Naming the Colours', Lewis (1997) makes an interesting claim about the relationship between linguistic and mental content; we are typically unable to read the content of a belief off the content of a sentence used to express that belief or vice versa. I call this view autonomism. I motivate and defend autonomism and discuss its importance in the philosophy of mind and language. In a nutshell, I argue that the different theoretical roles that mental and linguistic (...) content play suggest these kinds of content should be understood as sensitive to different things. (shrink)

Humean Supervenience is a metaphysical model of the world according to which all truths hold in virtue of nothing but the total spatiotemporal distribution of perfectly natural, intrinsic properties. David Lewis and others have worked out many aspects of HS in great detail. A larger motivational question, however, remains unanswered: As Lewis admits, there is strong evidence from fundamental physics that HS is false. What then is the purpose of defending HS? In this paper, we argue that the philosophical merit (...) of HS is largely independent of whether it correctly represents the world’s fundamental structure. In particular, we show that insofar as HS is an apt model of the world’s higher-level structure, it thereby provides a powerful argument for reductive physicalism and explains otherwise opaque inferential relations. Recent criticism of HS on the grounds that it misrepresents fundamental physical reality is, therefore, beside the point. (shrink)

This paper develops and defends the view that substantively normative uses of words like “good”, “right” and “ought” are irresolvably indeterminate: any single case of application is like a borderline case for a vague or indeterminate term, in that the meaning-fixing facts, together with the non-linguistic facts, fail to determine a truth-value for the target sentence in context. Normative claims, like vague or indeterminate borderline claims, are not meaningless, though. By making them, the speaker communicates information about the precisifications that (...) s/he accepts. The analogy with vague/indeterminate language, I argue, lays out a new and interesting foundation for a subjectivist approach to normativity. (shrink)

This chapter reviews four elements of David Lewis's account of materialism and experience. These elements include: materialism for which Lewis gave a distinctive and well‐known characterization; an account of what experience is; an account of the source of the tension between experience and materialism; and a strategy for resolving the tension. Lewis did not just give a distinctive and well‐known characterization of materialism, he gave two: one in terms of fundamental properties, and one in terms of supervenience. The chapter considers (...) two recent objections to that account. The first argues that knowledge‐how is a certain kind of knowledge‐that and in consequence Lewis's well‐known “ability hypothesis” fails. The second argues that if Lewis's contextualist approach to epistemology is correct, his rejection of the identification thesis is impossible. The author suggests that Lewis has the resources to answer both objections, but he ends by stating the real problems for Lewis's lie. (shrink)

Some truths about color are knowable a priori. For example, it is knowable a priori that redness is not identical to the property of being square. This extremely modest and plausible claim has significant philosophical implications, or so I shall argue. First, I show that this claim entails the falsity of standard forms of color functionalism, the view that our color concepts are functional concepts that pick out their referents by way of functional descriptions that make reference to the subjective (...) responses of perceivers. I then argue that, while some sophisticated forms of color functionalism can accommodate the a priori knowability of a truth like “redness is not identical to squareness,” they can only do so by abandoning color realism, the thesis that colors are instantiated by external material objects. In practice, color functionalists are almost invariably color realists. Thus, given extremely modest assumptions concerning what can be known a priori about color, we should conclude that color functionalism, at least in its typical realist form, is false. (shrink)

Current descriptivist accounts of proper names entail two claims: that the expressions we know as different proper names are the bearers of different meanings and that the descriptions corresponding to these meanings contain quotations of the expressions whose meanings they are taken to be. While is the source of a number of intractable problems, descriptivists feel committed to it because it is the only available option to adhere to, which they use to take as a matter of course. In the (...) present paper I will bring up for discussion a, to my knowledge, new descriptivist account, inter-nominal descriptivism, which avoids the commitment to by rejecting. According to this account, all tokens of the expressions known as different proper names express the same descriptive mode of presentation and this descriptive mode of presentation is akin to the character of an indexical. I will try to show that, contrary to first appearance, this idea can be developed in a consistent and plausible manner. (shrink)

© The Authors 2017. Published by Oxford University Press on behalf of The Analysis Trust. All rights reserved. For Permissions, please email: [email protected] Colour is a welcome work in history and philosophy of science.1 The opening chapters offer a fresh take on the history of perceptual theory and a broad overview of contemporary philosophy of colour. This is followed by the central fourth chapter, which introduces readers to a cluster of empirical data that to this point have not received explicit (...) treatment in philosophy. The core message is that instead of thinking of colour vision as filling in or painting the experienced world of primary qualities, we should think of colour vision as helping us to experience primary qualities. The colour visual system does not colour in an experiential world of primary qualities, it uses colour for the experience of those qualities. This colouring... (shrink)

Some intentional attitudes (beliefs, fears, desires, etc.) have a common focus in spite of there being no object at that focus. For example, two beliefs may be about the same witch even when there are no witches, different astronomers had beliefs directed at Vulcan, even though there is no such planet. This relation of having a common focus, whether or not there is an actual concrete object at that focus, is called intentional identity. In the first part of this thesis (...) I develop a new theory of intentional identity, the triangulation theory, and argue that it has significant advantages over the extant theories of intentional identity in the literature. Empty attitudes (attitudes that are not, prima facie, about anything that exists) will serve as useful cases for testing theories of intentional identity. -/- In the second part, I put the theory developed in the first part to work. I use triangulation theoretic tools to shed light on other debates about intentional attitudes. Some issues to which intentional identity are relevant are the debate about the content of intentional attitudes, the issue of whether or not we need to appeal to external constraints on the content of intentional attitudes, how we should understand the agreement and disagreement of attitudes, how we should construe communication and how we ought to solve Kripke’s puzzle about belief. The second part of this thesis also motivates a broadly internalist and individualistic approach to the con-tent of intentional attitudes; it turns out that if we take a closer look at the narrowly construed psychological states of agents we find materials that allow us to make sense of phenomena usually associated with externalist constraints on the content of attitudes (such as causal constraints and eligibility constraints) in a new way. (shrink)

In the present article, I show that sounds are properties that are not physical in a narrow sense. First, I argue that sounds are properties using Moorean style arguments and defend this property view from various arguments against it that make use of salient disanalogies between sounds and colors. The first disanalogy is that we talk of objects making sounds but not of objects making colors. The second is that we count and quantify over sounds but not colors. The third (...) is that sounds can survive qualitative change in their auditory properties, but colors cannot survive change in their chromatic properties. Next, I provide a taxonomy of property views of sound. As the property view of sound has been so rarely discussed, many of the views available have never been articulated. My taxonomy will articulate these views and how they are related to one another. I taxonomize sounds according to three characteristics: dispositional/non-dispositional, relational/non-relational, and reductive/non-reductive. Finally, mirroring a popular argument in the color literature, I argue that physical views in the narrow sense are unable to accommodate the similarity and difference relations in which sounds essentially stand. I end replying to three objections. (shrink)

Many prominent writers on the philosophy of logic, including Michael Dummett, Dag Prawitz, Neil Tennant, have held that the introduction and elimination rules of a logical connective must be ‘in harmony ’ if the connective is to possess a sense. This Harmony Thesis has been used to justify the choice of logic: in particular, supposed violations of it by the classical rules for negation have been the basis for arguments for switching from classical to intuitionistic logic. The Thesis has also (...) had an influence on the philosophy of language: some prominent writers in that area, notably Dummett and Robert Brandom, have taken it to be a special case of a more general requirement that the grounds for asserting a statement must cohere with its consequences. This essay considers various ways of making the Harmony Thesis precise and scrutinizes the most influential arguments for it. The verdict is negative: all the extant arguments for the Thesis are weak, and no version of it is remotely plausible. (shrink)

The phrase ‘in virtue of’ is a mainstay of metaphysical discourse. In recent years, many philosophers have argued that we should understand this phrase, as metaphysicians use it, in terms of a concept of metaphysical dependence called ‘grounding’.This dissertation explores a range of central issues in the theory of grounding. Chapter 1 introduces the intuitive concept of grounding and discusses some compulsory questions in the theory of grounding. Chapter 2 focusses on scepticism on grounding, according to which the recent philosophical (...) interest in the topic is misguided. In chapter 3 I discuss grounding’s explanatory roles. Chapter 4 focusses on the claim that if an entity is grounded then it is an ontological free lunch. Chapter 5 discusses and rejects the claim that groundingis a relation between facts. This conclusion raises a problem: if grounding is not a relation between facts it becomes difficult to specify the connections between grounding and explanation and grounding and necessity. But not only is it desirable to specify these relations, it is essential for establishing that grounding is able to play the explanatory roles that are discussed in chapter 3. Chapter 6 responds to this problem by outlining an approach to grounding based on David Lewis’s (2003) theory of truthmaking. Against this backdrop I discuss, in chapter 7, some issues in the logic of grounding. (shrink)

The topic of this paper is whether there is metaphysical vagueness. It is shown that it is important to distinguish between the general phenomenon of indeterminacy and the more narrow phenomenon of vagueness (the phenomenon that paradigmatically rears its head in sorites reasoning). Relatedly, it is important to distinguish between metaphysical indeterminacy and metaphysical vagueness. One can wish to allow metaphysical indeterminacy but rule out metaphysical vagueness. As is discussed in the paper, central argument against metaphysical vagueness, like those of (...) Gareth Evans and Mark Sainsbury, would if successful rule out metaphysical indeterminacy. One way to argue specifically against the possibility of metaphysical vagueness might be thought to be to argue for a specific theory of the nature of vagueness according to which vagueness is a semantic phenomenon. But it is shown that there are complications also pertaining to arguments with that structure. Toward the end of the paper, I discuss Trenton Merricks’ well-known argument against a semantic view on vagueness and for a metaphysical view. (shrink)

Magnetism in meta-semantics is the view that the meaning of our words is determined in part by their use and in part by the objective naturalness of candidate meanings. This hypothesis is commonly attributed to David Lewis, and has been put to philosophical work by Brian Weatherson, Ted Sider and others. I argue that there is no evidence that Lewis ever endorsed the view, and that his actual account of language reveals good reasons against it.

Two-dimensional (2D) semantics is a formal framework that is used to characterize the meaning of certain linguistic expressions and the entailment relations among sentences containing them. 2D semantics has also been applied to thought contents. In contrast with standard possible worlds semantics, 2D semantics assigns extensions and truth-values to expressions relative to two possible world parameters, rather than just one. So a 2D semantic framework provides finer-grained semantic values than those available within standard possible world semantics, while using the same (...) basic model-theoretic resources. The 2D framework itself is just a formal tool. To develop a semantic theory for someone’s language, a proponent of 2D semantics must do three things: (i) explain what exactly the two possible world parameters represent, (ii) explain the rules for assigning 2D semantic values to a person’s words and sentences, and (iii) explain how 2D semantic values help in understanding the meanings of the person’s words and sentences. (shrink)

Metaontology – the study of the nature of ontological issues – has flourished in recent years. The focus of this summary will be on some views and arguments that are central to today’s debate. One theme will be that of how seriously to take ontology: whether there is reason to take a skeptical or deflationary attitude toward ontological claims, as theorists like Rudolf Carnap, Hilary Putnam, and Eli Hirsch in different ways have urged. The other theme will be that of (...) the viability of the Fregean and Quinean approaches to ontology that have been and still are central to analytic philosophy. (shrink)

Vision scientists are interested in three diverse entities: physical stimuli, neural states, and consciously perceived colors, and in the mapping rules among the three. In this worldview, the three kinds of entities have coequal status, and views that attribute color exclusively to one or another of them, such as color realism, have no appeal.

In this commentary I argue that Byrne & Hilbert commit a number of philosophical solecisms: They beg the question of “realism,” they take the phenomenon and the theoretical model to be the same thing, and they surreptitiously substitute data sets for the life-world.

Byrne & Hilbert are right that it might be an objective fact that a particular tomato is unique red, but wrong that it cannot simultaneously be yellowish-red (not only objectively, but from somebody else's point of view). Sensory categorization varies among organisms, slightly among conspecifics, and sharply across taxa. There is no question of truth or falsity concerning choice of categories, only of utility and disutility. The appropriate framework for color categories is Nominalism and Pluralistic Realism.

“The problem of color realism” as defined in the first section of the target article, is crucial to the argument laid out by Byrne & Hilbert. They claim that the problem of color realism “does not concern, at least in the first instance, color language or color concepts” (sect. 1.1). I argue that this claim is misconceived and that a different characterisation of the problem, and some of their preliminary assumptions makes their positive proposal less appealing.

Byrne & Hilbert defend color realism, which assumes that: (a) colors are properties of objects; (b) these objects are physical; hence, (c) colors are physical properties. I accept (a), agree that in a certain sense (b) can be defended, but reject (c). Colors are properties of perceptual objects – which also have underlying physical properties – but they are not physical properties.

We argue that any theory of color physicalism must include consideration of ecological interactions. Ecological and sensorimotor contingencies resulting from relative surface motion and observer motion give rise to measurable effects on the spectrum of light reflecting from surfaces. These contingencies define invariant manifolds in a sensory-spatial space, which is the physical underpinning of all subjective color experiences.

Colors are of philosophical interest for two kinds of reason. One is that colors comprise such a large and important portion of our social, personal and epistemological lives and so a philosophical account of our concepts of color is highly desirable. The second reason is that trying to fit colors into accounts of metaphysics, epistemology and science leads to philosophical problems that are intriguing and hard to resolve. Not surprisingly, these two kinds of reasons are related. The fact that colors (...) are so significant in their own right, makes more pressing the philosophical problems of fitting them into more general metaphysical and epistemological frameworks. (shrink)

Many theorists hold that there is, among value concepts, a fundamental distinction between thin ones and thick ones. Among thin ones are concepts like good and right. Among concepts that have been regarded as thick are discretion, caution, enterprise, industry, assiduity, frugality, economy, good sense, prudence, discernment, treachery, promise, brutality, courage, coward, lie, gratitude, lewd, perverted, rude, glorious, graceful, exploited, and, of course, many others. Roughly speaking, thick concepts are value concepts with significant descriptive content. I will discuss a number (...) of problems having to do with how best to understand the notion of a thick concept. Thick concepts have been widely discussed in the .. (shrink)

In this paper I outline an alternative to hermeneutic fictionalism, an alternative I call indifferentism, with the same advantages as hermeneutic fictionalism with respect to ontological issues but avoiding some of the problems that face fictionalism. The difference between indifferentism and fictionalism is this. The fictionalist about ordinary utterances of a sentence S holds, with more orthodox views, that the speaker in some sense commits herself to the truth of S. It is only that for the fictionalist this is truth (...) in the relevant fiction. According to the indifferentist, by contrast, we are simply non-committal – or indifferent – with respect to some aspects of what is literally said in our assertive utterances. (shrink)

I propose a strategy for a metaphysical reduction of perceived color, that is, an identification of perceived color with properties characterizable in non-qualitative terms. According to this strategy, a description of visual experience of color, which incorporates a description of the appearance of color, is a reference-fixing description. This strategy both takes color appearance seriously in its primary epistemic role and avoids rendering color as metaphysically mysterious. I’ll also argue that given this strategy, a plausible account of perceived color claims (...) that colors are physical properties of physical objects. (shrink)

Chomsky and others have denied the relevance of external linguistic entities, such as E-languages, to linguistic explanation, and have questioned their coherence altogether. I discuss a new approach to understanding the nature of linguistic entities, focusing in particular on making sense of the varieties of kinds of “words” that are employed in linguistic theorizing. This treatment of linguistic entities in general is applied to constructing an understanding of external linguistic entities.

Our reply is in three parts. The first part concerns some foundational issues in the debate about color realism. The second part addresses the many objections to the version of physicalism about color ("productance physicalism") defended in the target article. The third part discusses the leading alternative approaches and theories endorsed by the commentators.

Physicalism is the thesis that everything is physical, or as contemporary philosophers sometimes put it, that everything supervenes on, or is necessitated by, the physical. The thesis is usually intended as a metaphysical thesis, parallel to the thesis attributed to the ancient Greek philosopher Thales, that everything is water, or the idealism of the 18th Century philosopher Berkeley, that everything is mental. The general idea is that the nature of the actual world (i.e. the universe and everything in it) conforms (...) to a certain condition, the condition of being physical. Of course, physicalists don't deny that the world might contain many items that at first glance don't seem physical — items of a biological, or psychological, or moral, or social nature. But they insist nevertheless that at the end of the day such items are either physical or supervene on the physical. (shrink)

Physicalism about colour is the thesis that colours are identical with response-independent, physical properties of objects. I endorse the Argument from Structure against Physicalism about colour. The argument states that Physicalism cannot accommodate certain obvious facts about colour structure: for instance, that red is a unitary colour while purple is a binary colour, and that blue resembles purple more than green. I provide a detailed formulation of the argument. According to the most popular response to the argument, the Physicalist can (...) accommodate colour structure by explaining it in terms of colour experience. I argue that this response fails. Along the way, I examine other interesting issues in the philosophy of colour and colour perception, for instance the relational structure of colour experience and the description theory of how colour names refer. (shrink)

According to colour irrealism, material objects do not have colour; they only appear to have colour. The appeal of this view, prominent among philosophers and scientists alike, stems in large part from the conviction that scientific explanations of colour facts do not ascribe colour to material objects. To explain why objects appear to have colour, for instance, we need only appeal to surface reflectance properties, properties of light, the neurophysiology of observers, etc. Typically attending colour irrealism is the error theory (...) of ordinary colour judgement: ordinary judgements in which colour is ascribed to a material object are, strictly speaking, false. In this paper, I claim that colour irrealists who endorse the error theory cannot explain how we acquire colour concepts (yellow, green, etc.), concepts they must acknowledge we do possess. Our basic colour concepts, I argue, could not be phenomenal concepts that we acquire by attending to the colour properties of our experience. And, I explain, all other plausible explanations render colour concepts such that our ordinary colour judgements involving them are often true. Given the explanatory considerations upon which the irrealist's position is based, this is a severe problem for colour irrealism. (shrink)

Anything is similar to anything, provided the respects of similarity are allowed to be gerrymandered or gruesome, as Goodman observed.2 But similarity in non-gruesome or—as I shall say—genuine respects is much less ecumenical. Colors, it seems, provide a compelling illustration of the distinction as applied to similarities among properties.3 For instance, in innumerable gruesome respects, blue is more similar to yellow than to purple. But in a genuine respect, blue is more similar to purple than to yellow (genuinely more similar, (...) as I shall sometimes put it). (shrink)

The target article is an attempt to make some progress on the problem of color realism. Are objects colored? And what is the nature of the color properties? We defend the view that physical objects (for instance, tomatoes, radishes, and rubies) are colored, and that colors are physical properties, specifically types of reflectance. This is probably a minority opinion, at least among color scientists. Textbooks frequently claim that physical objects are not colored, and that the colors are "subjective" or "in (...) the mind." The article has two other purposes: first, to introduce an interdisciplinary audience to some distinctively philosophical tools that are useful in tackling the problem of color realism and, second, to clarify the various positions and central arguments in the debate. (shrink)

Are colors relational or non-relational properties of their bearers? Is red a property that is instantiated by all and only the objects with a certain intrinsic (/non-relational) nature? Or does an object with a particular intrinsic (/non-relational) nature count as red only in virtue of standing in certain relations - for example, only when it looks a certain way to a certain perceiver, or only in certain circumstances of observation? In this paper I shall argue for the view that color (...) properties are relational (henceforth, relationalism), and against the view that colors are not relational (henceforth, anti- or non-relationalism). (shrink)

Primary quality theories of color claim that colors are intrinsic, objective, mind-independent properties of external objects — that colors, like size and shape, are examples of the sort of properties moderns such as Boyle and Locke called primary qualities of body.¹ Primary quality theories have long been seen as one of the main philosophical options for understanding the nature of color.

(Tye 2006) presents us with the following scenario: John and Jane are both stan- dard human visual perceivers (according to the Ishihara test or the Farnsworth test, for example) viewing the same surface of Munsell chip 527 in standard conditions of visual observation. The surface of the chip looks “true blue” to John (i.e., it looks blue not tinged with any other colour to John), and blue tinged with green to Jane.¹ Tye then in effect poses a multiple choice question.

Our reading is a passage from John Locke, An Essay Concerning Human Understanding , Book III, Chapter II, § 2. When a man speaks to another, it is that he may be understood; and the end of speech is that those sounds, as marks, may make known his ideas to the hearer. … Words being voluntary signs, they cannot be voluntary signs imposed by him on things he knows not. That would be to make them signs of nothing, sounds without (...) signification. (shrink)

I here defend microphysical manyism. According to microphysical manyism, each composite or higher-level object is a mere plurality of microphysical particles. After clarifying the commitments of the view, I offer two physicalist-friendly arguments in its favour. The first argument appeals to the Canberra Plan. Here I argue that microphysical particles acting in unison play the theoretical roles associated with composite objects - that they do everything that we think of composite objects as doing - and thus that composite objects are (...) to be identified with pluralities of microphysical particles. Along the way I rebut the objections that pluralities of particles don’t display the right emergent, ‘lingering’, or modal properties to be good candidates for identification with higher-level objects. In the second argument I claim that microphysical manyism is uniquely able to capture a compelling and widespread physicalist intuition concerning the intimate nature of the relationship between higher-level, composite objects and the microphysical world. (shrink)

Modal dispositionalism is the view that possibilities are a matter of the dispositions of individual objects: it is possible that p if and only if something has a disposition for p to be the case. We raise a problem for modal dispositionalism: nothing within the theory rules out that there could be necessary, perfect masks, which make the manifestation of a disposition impossible. Unless such necessary perfect masks are ruled out, modal dispositionalism runs the risk of failing to provide a (...) sufficient condition for possibility, and indeed of engendering contradictions. But to rule them out, modal dispositionalism would have to revise a crucial tenet of the view, its localism. (shrink)

In the Addenda to Naming and Necessity (1980), Kripke famously argues that it is false that there could have been unicorns, or more properly, that “no counterfactual situation is properly describable as one in which there would have been unicorns.” He adds that he holds similarly that ‘one cannot say of any possible person that he would have been Sherlock Holmes, had he existed.” He notes the “cryptic brevity” of these remarks and refers to a forthcoming work for elaborations—the work (...) being, of course, the John Locke Lectures (2013). Coming as it does at the end of Naming and Necessity, it is natural to read this discussion as drawing out consequences of Kripke’s non-descriptivist picture of proper names and names of natural kinds. In fact, so much is suggested there by Kripke himself. The question thus arises: can the contentious claims quoted from the Addenda be defended independently of Kripke’s rejection of descriptivism? I shall argue that, as appears from the John Locke Lectures, they can be. (shrink)

A popular approach in philosophy, the so-called Canberra Plan, is critically scrutinized. Two aspects of this research program, the formal and the informal program, are distinguished. It is argued that the formal program runs up against certain serious technical problems. It is also argued that the informal program involves an unclear leap at its core. Consequently, it is argued that the whole program is much more problematic than its advocates recognize.

Following the influential thought experiments by Hilary Putnam and others, philosophers of language have for the most part adopted semantic externalism concerning natural kind terms. In this article, we present results from three experiments on the reference of natural kind terms. Our results confirm some standard externalist assumptions, but are in conflict with others: Ordinary speakers take both appearance and underlying nature to be central in their categorization judgments. Moreover, our results indicate that speakers’ categorization judgments are gradual, and proportional (...) to the degree of similarity between new samples and familiar, “standard” samples. These findings pose problems for traditional theories, both externalist and internalist. (shrink)

What is objectivity? What would it take to have objective representations and do we have what it takes? This paper aims to contribute to answering these questions. To this end, it isolates one relevant sense of objectivity and proposes a generalization of standard frameworks of representational content in order to engage with the question in a way that is rhetorically fair. Armed with a general conception of perspectival content, taken from the literature on centred or de se content, the paper (...) articulates one necessary condition for objective representation: the possession of objective concepts and therefore objective contents. Two ways of meeting this condition are discussed in an exploratory way. (shrink)

De se attitudes seem to play a special role in action and cognition. This raises a challenge to the traditional way in which mental attitudes have been understood. In this chapter, we review the case for thinking that de se attitudes require special theoretical treatment and discuss various ways in which the traditional theory can be modified to accommodate de se attitudes.

In the philosophy of mind, revelation is the claim that the nature of qualia is revealed in phenomenal experience. In the literature, revelation is often thought of as intuitive but in tension with physicalism. While mentions of revelation are frequent, there is room for further discussion of how precisely to formulate the thesis of revelation and what it exactly amounts to. Drawing on the work of David Lewis, this paper provides a detailed discussion on how the thesis of revelation, as (...) well as its incompatibility with physicalism, is to be understood. (shrink)

Many philosophers think that moral objectivism is supported by stable features of moral discourse and thinking. When engaged in moral reasoning and discourse, people behave ‘as if’ objectivism were correct, and the seemingly most straightforward way of making sense of this is to assume that objectivism is correct; this is how we think that such behavior is explained in paradigmatically objectivist domains. By comparison, relativist, error-theoretic or non-cognitivist accounts of this behavior seem contrived and ad hoc. After explaining why this (...) argument should be taken seriously (recent arguments notwithstanding), I argue that it is nevertheless undermined by considerations of moral disagreement. Even if the metaphysical, epistemic and semantic commitments of objectivism provide little or no evidence against it, and even if the alternative explanations of ‘objectivist’ traits of moral discourse and thinking are speculative or contrived, objectivism is itself incapable of making straightforward sense of these traits. Deep and widespread moral disagreement or, rather, the mere appearance of such disagreement, strongly suggests that the explanations operative in paradigmatically objective discourse fail to carry over to the moral case. Since objectivism, no less than relativism, non-cognitivism and error-theories, needs non-trivial explanations of why we behave ‘as if’ objectivism were correct, such behavior does not presently provide reason to accept objectivism. (shrink)