forthcoming in Philosophy and Phenomenological Research.

According to Quine, in any disagreement over basic logical laws the contesting parties must mean different things by the connectives or quantifiers implicated in those laws; when a deviant logician ‘tries to deny the doctrine he only changes the subject’. The standard semantics for intuitionism offers some confirmation for this thesis, for it represents an intuitionist as attaching quite different senses to the connectives than does a classical logician. All the same, I think Quine was wrong, even about the dispute (...) between classicists and intuitionists. I argue for this by presenting an account of consequence, and a cognate semantic theory for the language of the propositional calculus, which respects the meanings of the connectives as embodied in the familiar classical truth-tables, does not presuppose Bivalence, and with respect to which the rules of the intuitionist propositional calculus are sound and complete. Thus the disagreement between classicists and intuitionists, at least, need not stem from their attaching different senses to the connectives; one may deny the doctrine without changing the subject. The basic notion of my semantic theory is truth at a possibility, where a possibility is a way that things might be, but which differs from a possible world in that the way in question need not be fully specific or determinate. I compare my approach with a previous theory of truth at a possibility due to Lloyd Humberstone, and with a previous attempt to refute Quine’s thesis due to John McDowell. (shrink)

A number of philosophers defend naturalistic moral realism by appeal to an externalist semantics for moral predicates. The application of semantic externalism to moral predicates has been attacked by Terence Horgan and Mark Timmons in a series of papers that make use of their “ Moral Twin Earth ” thought experiment. In response, several defenders of naturalistic moral realism have claimed that the Moral Twin Earth thought experiment is misleading and yields distorted and inaccurate semantic intuitions. If they are right, (...) the intuitions generated by Moral Twin Earth cannot be appealed to in arguments against externalist moral semantics. The most developed case against the Moral Twin Earth argument that follows this strategy is found in a paper by Stephen Laurence, Eric Margolis and Angus Dawson. Here I argue that their attack on the Moral Twin Earth thought experiment fails. Laurence, Margolis and Dawson have not shown that we have reason to distrust the semantic intuitions it generates. (shrink)

According to Michael Devitt, the primary work of a rigidity distinction for kind terms is to distinguish non-descriptional predicates from descriptional predicates. The standard conception of rigidity fails to do this work when it is extended to kind terms. Against the standard conception, Devitt defends rigid application: a predicate is a rigid applier iff, if it applies to an object in one world, it applies to that object in every world in which it exists. Devitt maintains that rigid application does (...) the job of identifying nondescriptional predicates perfectly. I argue that Devitt is wrong about this. When we examine more closely alternative theories about the identity and persistence conditions of those entities to which mass terms apply, we find no plausible theory that has the result that a term is rigid iff it is non-descriptional. (shrink)

The question of whether cognition requires representations has engendered heated discussion during the last two decades. I shall argue that the question is, in all likelihood, a spurious one. There may or may not be a fact of the matter concerning whether a given item qualifies as a representation. However, even if there is, attempts to establish whether cognition requires representation have neither practical nor theoretical utility.

This survey of major developments in North American philosophy of science begins with the mid-1960s consolidation of the disciplinary synthesis of internalist history and philosophy of science (HPS) as a response to criticisms of logical empiricism. These developments are grouped for discussion under the following headings: historical metamethodologies, scientific realisms, philosophies of the special sciences, revivals of empiricism, cognitivist naturalisms, social epistemologies, feminist theories of science, studies of experiment and the disunity of science, and studies of science as practice and (...) culture. A unifying theme of the survey is the relation between historical metamethodologists and scientific realists, which dominated philosophical work in the late 1970s. I argue that many of the alternative cognitive naturalisms, social epistemologies, and feminist theories that have been proposed can be understood as analogues to the differences between metamethodological theories of scientific rationality and realist accounts of successful reference to real causal processes. Recent work on experiment, scientific practice, and the culture of science may, however, challenge the underlying conception of the field according to which realism and historical rationalism (or their descendants) are the important alternatives available, and thus may take philosophy of science in new directions. (shrink)

The major goal of René Descartes’s rich and penetrating recent book, Meditations on First Philosophy, is to develop a methodology for the discovery of the truth, more specifically, a methodology that accommodates the dictates of a mathematical physics for our view of physical reality. Such a methodology must accordingly deal with and seek to defuse the apparent conflict between a mathematical physics and our commonsense picture of things, a conflict that continues to pose difficult challenges. Though much in the book (...) is devoted to an account of the mind, that focus results from the broader goal of finding a methodology for discovery that will deliver an overall picture of reality consonant with a mathematical physics. Much that Descartes says in this book may strike many readers as extravagant and implausible, and perhaps hardly worth serious consideration. But there is a line of argument one can extract that is challenging and often compelling, even if not in the end wholly convincin .. (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)

In 1907, Alfred Stieglitz took what was to become one of his signature photographs, The Steerage. Stieglitz stood at the rear of the ocean liner Kaiser Wilhelm II and photographed the decks, first-class passengers above and steerage passengers below, carefully exposing the film to their reflected light. Later, in the darkroom, Stieglitz developed this film and made a number of prints from the resulting negative. The photograph is a familiar one, an enduring piece of social commentary, but what exactly is (...) The Steerage which Stieglitz has given us? It is clearer what The Steerage is not. It is distinct from each of its prints and from its negative. These may be dusty or torn without The Steerage being so, and any one of these could be destroyed without thereby destroying The Steerage itself. Nor is The Steerage the set of its prints. The set could not have had different members, while The Steerage could have had more, fewer, or different prints.1 Similar reasoning rules out the mereological sum of parts of its actual prints, for The Steerage’s prints might not have comprised just these parts. We are left with a puzzle, what sort of thing is a photograph? This puzzle is not unique to photography. Similar reasoning generates an analogous puzzle for any repeatable work of art. Novels, poems, plays, symphonies, songs, and the rest share an ontological predicament and create a 1 general puzzle concerning the ontological status of repeatable works of art. It is widely held that the puzzle has an equally general solution, one which I will argue fails for systematic reasons. Although my target here is the supposed solution to the general problem, photography will remain the central case under scrutiny. I offer it as a model for our thinking about the wider class in order to reap the benefits of thinking in terms of concrete cases. Although this risks a trade-off with the generality of my conclusions—there are important differences of detail between the cases—I hope it is clear that the considerations I appeal to in photography are not idiosyncratic but shared by the wider class.. (shrink)

According to Essentialism, an object’s properties divide into those that are essential and those that are accidental. While being human is commonly thought to be essential to Socrates, being a philosopher plausibly is not. We can motivate the distinction by appealing—as we just did—to examples. However, it is not obvious how best to characterize the notion of essential property, nor is it easy to give conclusive arguments for the essentiality of a given property. In this paper, I elaborate on these (...) issues and explore the way in which essential properties behave in relation to other related properties, like sufficient-for-existence properties and individual essences. (shrink)

The paper presents a dilemma for both epistemic and non-epistemic versions of conceivability-based accounts of modal knowledge. On the one horn, non-epistemic accounts do not elucidate the essentialist knowledge they would be committed to. On the other, epistemic accounts do not elucidate everyday life de re modal knowledge. In neither case, therefore, do conceivability accounts elucidate de re modal knowledge.

Laws of nature are puzzling because they have a 'modal character'—they seem to be 'necessary-ish'—even though they also seem to be metaphysically contingent. And it is hard to understand how contingent truths could have such a modal character. Scientific essentialism is a doctrine that seems to dissolve this puzzle, by showing that laws of nature are actually metaphysically necessary. I argue that even if the metaphysics of natural kinds and properties offered by scientific essentialism is correct, there are still some (...) metaphysically contingent truths that share the modal character of the laws of nature. I argue that these contingent truths should be considered laws of nature. So even if scientific essentialism is true, at least some laws of nature are metaphysically contingent. (shrink)

Color relationalism holds that the colors are constituted by relations to subjects. The introspective rejoinder against this view claims that it is opposed to our phenomenally-informed, pre-theoretic intuitions. The rejoinder seems to be correct about how colors appear when looking at how participants respond to an item about the metaphysical nature of color but not when looking at an item about the ascription of colors. The present article expands the properties investigated to sound and taste and inspects the mentioned asymmetry, (...) with a particular focus on the principle of charity. Using a metaphysical item, we find that color and sound are no different from shape, our control for a clearly anti-relational property. Taste, on the other hand, is no different from likability, our control for a clearly relational property. Importantly, we find that the disparity between metaphysical and ascription items is due to participants using a principle of charity to interpret disagreement cases such that both parties can be correct. (shrink)

Hidden nature physicalists hold that an experiential quality and its hidden nature are the same property – even though they agree that our experiences are of experiential qualities but are not, in the same sense, experiences of their hidden natures. This paper argues that physicalists must be committed to ultimately giving accounts that involve no non-extensional relations, and that this commitment leads to an inability to explain how our experiences could be of experiential qualities, but not of their hidden natures.

Colour relationalism holds that the colours are constituted by relations to subjects. Anti-relationalists have claimed that this view stands in stark contrast to our phenomenally-informed, pre-theoretic intuitions. Is this claim right? Cohen and Nichols’ recent empirical study suggests not, as about half of their participants seemed to be relationalists about colour. Despite Cohen and Nichols’ study, we think that the anti-relationalist’s claim is correct. We explain why there are good reasons to suspect that Cohen and Nichols’ experimental design skewed their (...) results in favour of relationalism. We then run an improved study and find that most of our participants seem to be anti-relationalists. We find some other interesting things too. Our results suggest that the majority of ordinary people find it no less intuitive that colours are objective than that shapes are objective. We also find some evidence that when those with little philosophical training are asked about the colours of objects, their intuitions about colour and shape cases are similar, but when asked about people’s colour ascriptions, their intuitions about colour and shape cases differ. (shrink)

Intrapersonal variation due to color contrast effects has been used to argue against the following intuitive propositions about the colors: No object can be more than one determinable or determinate color of the same grade all over at the same time ; external objects are actually colored ; and the colors of objects are mind-independent. In this article, I provide a defense of Incompatibility, Realism, and Objectivism from intrapersonal variation arguments that rely on color contrast effects. I provide a novel, (...) ecumenical response to such arguments according to which typical variants are right, and which respects Incompatibility, Realism, and Objectivism, using the thesis that the colors of objects depend on the colors of objects in their surrounds. (shrink)

Social groups, including racial and gender groups and teams and committees, seem to play an important role in our world. This article examines key metaphysical questions regarding groups. I examine answers to the question ‘Do groups exist?’ I argue that worries about puzzles of composition, motivations to accept methodological individualism, and a rejection of Racialism support a negative answer to the question. An affirmative answer is supported by arguments that groups are efficacious, indispensible to our best theories, and accepted given (...) common sense. Then, I turn to an examination of the features of social groups. I argue that social groups can be divided into two sorts. Groups of Type 1 are organized social groups like courts and clubs. Groups of Type 2 are groups like Blacks, women, and lesbians. While groups of both sorts have some features in common, they also have marked differences in features. Finally, I turn to views of the nature of social groups. I argue that the difference in features provides evidence that social groups do not have a uniform nature. Teams and committees are structured wholes, while race and gender groups are social kinds. (shrink)

This paper discusses two distinct strategies that have been adopted to provide fine-grained propositions; that is, propositions individuated more finely than sets of possible worlds. One strategy takes propositions to have internal structure, while the other looks beyond possible worlds, and takes propositions to be sets of circumstances, where possible worlds do not exhaust the circumstances. The usual arguments for these positions turn on fineness-of-grain issues: just how finely should propositions be individuated? Here, I compare the two strategies with an (...) eye to the fineness-of-grain question, arguing that when a wide enough range of data is considered, we can see that a circumstance-based approach, properly spelled out, outperforms a structure-based approach in answering the question. (Part of this argument involves spelling out what I take to be a reasonable circumstance-based approach.) An argument to the contrary, due to Soames, is also considered. (shrink)

This article explores some fundamental issues of definition-based lexical semantic research through a critique of the Natural Semantic Metalanguage (NSM) theory of semantic and grammatical description (Wierzbicka 1996, Semantics. Primes and Universals, Oxford University Press, Oxford). NSM is criticized for attaching excessive importance to explanatory definition, for its adoption of the reductive requirement that a definiens be simpler than a definiendum, and for its use of ‘canonical contexts’ to disambiguate meaning. The principle of substitutability, according to which a definition of (...) a term is accepted if it can be substituted for the term itself, is also critically examined, and the theory’s use of syntactic phenomena as evidence for polysemy is shown to be inconsistent. Finally, suggestions that NSM may be a valid analytical method for only a subpart of the lexicon are rejected. (shrink)

A long-standing debate has dominated systematic biology and the ontological commitments made by its theories. The debate has contrasted individuals and the part – whole relationship with classes and the membership relation. This essay proposes to conceptualize the hierarchy of higher taxa is terms of a hierarchy of homeostatic property cluster natural kinds (biological species remain largely excluded from the present discussion). The reference of natural kind terms that apply to supraspecific taxa is initially fixed descriptively; the extension of those (...) natural kind terms is subsequently established by empirical investigation. In that sense, classification precedes generalization, and description provides guidance to empirical investigation. The reconstruction of a hierarchy of (homeostatic property cluster) natural kinds is discussed in the light of cladistic methods of phylogeny reconstruction. (shrink)

This paper takes a hierarchical approach to the question whether species are individuals or natural kinds. The thesis defended here is that species are spatiotemporally located complex wholes (individuals), that are composed of (i.e., include) causally interdependent parts, which collectively also instantiate a homeostatic property cluster (HPC) natural kind. Species may form open or closed genetic systems that are dynamic in nature, that have fuzzy boundaries due to the processual nature of speciation, that may have leaky boundaries as is manifest (...) in lateral gene transfer and introgression, that may be of multiple origins through hybridization, and that may split and merge and split again over time. The identity conditions of species qua individuals will have to be anchored in their history, rather than in their unique evolutionary origin. Species qua historically conditioned HPC natural kinds requires the kind to be mereologically structured, subject to the part-whole relation rather than the membership relation. This implies that there can be more than one kind of natural kinds. (shrink)

John MacFarlane has made relativism popular again. Focusing just on his original discussion, I argue that the data he uses to motivate the position do not, in fact, motivatie it at all. Many of the points made here have since been made, independently, by Hermann Cappelen and John Hawthorne, in their book Relativism and Monadic Truth.

In her recent (2009) book, The Origins of Concepts, Susan Carey argues that what she calls ‘Quinean Bootstrapping’ and processes of analogy in children show that the expressive power of a mind can be increased in ways that refute Jerry Fodor's (1975, 2008) ‘Mad Dog’ view that all concepts are innate. I argue that it is doubtful any evidence about the manifestation of concepts in children will bear upon the logico-semantic issues of expressive power. Analogy and bootstrapping may be ways (...) to bring about the former, but only by presupposing the very expressive powers Carey is claiming they explain. Analogies must be understood, and bootstrapping involves confirmation of hypotheses already expressible; otherwise they can't select among an infinitude of hypotheses compatible with the finite data the child has encountered, a fact rendered vivid by Goodman's ‘grue’ paradox and Chomsky's poverty of stimulus argument. The problems have special application to minds, since there is no reason to expect a child's concepts to be ‘projectible’ or to correspond to mind-independent natural kinds. I conclude with an ecumenical view that concepts are reasonably regarded as both innate and often learned, and that what is learned can in fact increase what really concerns Carey, the functioning psychological expressive power of the child, even if it leaves untouched what concerns Fodor, the semantic expressive power. Less ecumenically: maybe Fodor (2008) miscast the debate, and the real issue that bothers people concerns not nativism, but an issue on which Carey and Fodor surprisingly agree, his conceptual Atomism, or the view that all mono-morphemic concepts are primitive and unanalyzable. The issue deserves further discussion independently of Mad-doggery. (shrink)

Machery neglects the crucial role of concepts in psychological explanation, as well as the efforts of numerous of the last 40 years to provide an account of that role. He rightly calls attention to the wide variation in people's epistemic relations to concepts but fails to appreciate how externalist and kindred proposals offer the needed stability in concepts themselves that underlies that variation.

ABSTRACT Historical structuralist views have been ontological. They either deny that there are any mathematical objects or they maintain that mathematical objects are structures or positions in them. Non-ontological structuralism offers no account of the nature of mathematical objects. My own structuralism has evolved from an early sui generis version to a non-ontological version that embraces Quine’s doctrine of ontological relativity. In this paper I further develop and explain this view.

One of the most important objections to information-based semantic theories is that they are incapable of explaining Frege cases. The worry is that if a concept’s intentional content is a function of its informational content, as such theories propose, then it would appear that coreferring expressions have to be synonymous, and if this is true, it’s difficult to see how an agent could believe that a is F without believing that b is F whenever a and b are identical. I (...) argue that this appearance is deceptive. If we heed the distinction between the analog and digital contents of a signal, it is actually possible to reconstruct something akin to Frege’s sense/reference distinction in purely information-theoretic terms. This allows informational semanticists to treat coreferring expressions as semantically distinct and to solve Frege cases in the same way that Frege did—namely, by appealing to the different contents of coreferring expressions. (shrink)

Philosophers interested in the fitting attitude analysis of final value have devoted a great deal of attention to the wrong kind of reasons problem. This paper offers an example of the reverse difficulty, the wrong kind of value problem. This problem creates deeper challenges for the fitting attitude analysis and provides independent grounds for rejecting it, or at least for doubting seriously its correctness.

Famously, Saul Kripke proposes that there are contingent a priori truths, and has offered a number of examples to illustrate his claim. The most well-known example involves the standard meter bar in Paris. Purportedly, a certain agent knows a priori that the bar is one meter long. However, in response to a long-standing objection to such examples - the "existential complaint" - generally only modified examples having a conditional form are now considered candidates for the contingent a priori. Gareth Evans (...) argues that these conditionals must be understood free-logically, and on this basis argues against Keith Donnellan's analysis of the contingent a priori. I show Evans' argument mistaken. I also take issue with the existential complaint, and suggest a way of understanding Kripke's original examples that is not subject to it. My approach focuses the debate in its right place, and allows us to take Kripke's original examples seriously. (shrink)

We think about and refer to things that we’ve never perceived or experienced. This paper bears on how this could be. Someone is testimonially acquainted with something just in case the explanation of one’s ability to think de re thoughts about it essentially appeals to communication with others who already have that ability. The main motivation for the claim that testimonial acquaintance is possible is that it best explains how we can think de re about and refer to things we’ve (...) never perceived or experienced: we gain these abilities in part by communicating with those who already have them. The main point of this paper is negative: to argue that testimonial acquaintance, as we currently understand it, is impossible. Although one might take this to show that we cannot be acquainted with things we haven’t perceived or experienced, I prefer to think of it as motivation for rethinking the nature of acquaintance. (shrink)

Use theories of meaning (UTMs) seem ill-equipped to accommodate the intuition that ignorant but deferential speakers use natural kind terms (e.g. 'zinc') and technical expression (e.g. 'credit default swap') with the same meanings as the experts do. After all, their use deviates from the experts', and if use determines meaning, a deviant use ordinarily would determine a deviant meaning. Yet the intuition is plausible and advocates of UTMs believe it can be accommodated. I examine Gilbert Harman's and Paul Horwich's views, (...) and argue that they do not offer a satisfactory reconciliation of the intuition with the theory. I propose an accommodation based on a novel account of semantic deference, and show that it is consistent with UTMs that a speaker may use a word with a certain meaning without fully or adequately knowing it. (shrink)

Busshō, one of the central fascicles of Dōgen’s Shōbōgenzō, is dedicated to the problematic of Buddha-nature, the understanding of which in Dōgen’s thought is fairly different from previous Buddhist philosophy, but concordant with his views on reality, time and person. The article will present a close reading of several passages of the fascicle with comment in order to argue that Dōgen’s understanding of Buddha-nature is not something that entities have, but a mode of how they are, neither in itself nor (...) for us, but in the total world-process. The relation between totality and particularity is not hierarchical, nor one of opposition, but conceived of a matter of perspective, which, as Dōgen shows, is both mediated and circumscribed by language. As a result, we can see that particularity of being is precisely what makes the totality of being accessible to every existent, not an obstacle to be overcome. (shrink)

According to the orthodox account of meaning and translation in the literature, meaning is a property of expressions of a language, and translation is a matching of synonymous expressions across languages. This linguistic account of translation gives rise to well-known skeptical conclusions about translation, objectivity, meaning and truth, but it does not conform to our best translational practices. In contrast, I argue for a textual account of meaning based on the concept of a TEXT-TYPE that does conform to our best (...) translational practices. With their semantic function in view, text-types are Archimedean points for their respective disciplines. The text-type of philosophy is no exception. Culture-transcendent conceptual analysis can proceed on firm footing without having to deny the reality of radical cultural and linguistic difference by treating components of text-types as the concepts to be analyzed. Analyses of central philosophical concepts are provided as a means of adjudicating philosophical controversy. (shrink)

In this essay I will defend a novel version of the indexical view on proper names. According to this version, proper names have a relatively sparse truth-conditional meaning that is represented by their rigid content and indexical character, but a relatively rich use-conditional meaning, which I call the (contextual) constraint of a proper name. Firstly, I will provide a brief outline of my favoured indexical view on names in contrast to other indexical views proposed in the relevant literature. Secondly, two (...) general motivations for an indexical view on names will be introduced and defended. Thirdly, I will criticize the two most popular versions of the indexical view on names: formal variable accounts and salience-based formal constant accounts. In the fourth and final section, I will develop my own use-conditional indexical view on names in three different steps by confronting an initial version of this view with three different challenges. (shrink)

The predicate view on proper names opts for a uniform semantic representation of proper nouns like ‘Alfred’ as predicates on the level of logical form. Early defences of this view can be found in Sloat (Language, vol. 45, pp. 26–30, 1969) and Burge (J. Philos. 70: 425–439, 1973), but there is an increasing more recent interest in this view on proper names. My paper aims to provide a reconstruction and critique of Burge’s main argument for the predicate view on proper (...) names, which is still used by several current philosophers in defence of this view. I have called this argument the unification argument. I will present a stepwise interpretation and reconstruction of this argument, consider several possible responses to it and defend a specific response to it in detail. (shrink)

In this paper, I explore the implications of recent empirical research on concept representation for the philosophical enterprise of conceptual analysis. I argue that conceptual analysis, as it is commonly practiced, is committed to certain assumptions about the nature of our intuitive categorization judgments. I then try to show how these assumptions clash with contemporary accounts of concept representation in cognitive psychology. After entertaining an objection to my argument, I close by considering ways in which conceptual analysis might be altered (...) to accord better with the empirical work. (shrink)

A popular argument supporting functionalism has been what is commonly called the “multiple realizability” argument. One version of this argument uses thought experiments designed to show that minds could be composed of different types of material. This article offers a metaphilosophical analysis of this argument and shows that it fails to provide a strong case for functionalism. The multiple realizability argument is best understood as an inference‐to‐the‐best‐explanation argument, whereby a functionalist account of our mental concepts serves to explain our multiple (...) realizability intuitions. I show that the argument is inadequate because alternative accounts of our mental concepts exist that provide equally plausible explanations for these intuitions. Moreover, in the case of our qualia concepts, a nonfunctionalist account explains several other intuitions that functionalism cannot explain. Thus, despite its popularity, the intuition‐based version of the multiple realizability argument is a poor reason for accepting functionalism. (shrink)

The idea that there are features of or in our conscious experience that are, in some important sense, private has both a long history in philosophy and a large measure of intuitive attraction. Once this idea is in place, it will be very natural to assume that one can think and judge about one’s own private features. And it is then only a small step to the idea that we might communicate such thoughts and judgements about our respective private features (...) with each other. (shrink)

The paper argues that the reference of perceptual demonstratives is fixed in a causal nondescriptive way through the nonconceptual content of perception. That content consists first in spatiotemporal information establishing the existence of a separate persistent object retrieved from a visual scene by the perceptual object segmentation processes that open an object-file for that object. Nonconceptual content also consists in other transducable information, that is, information that is retrieved directly in a bottom-up way from the scene (motion, shape, etc). The (...) nonconceptual content of the mental states induced when one uses a perceptual demonstrative constitutes the mode of presentation of the perceptual demonstrative that individuates but does not identify the object of perceptual awareness and allows reference to it. On that account, perceptual demonstratives put us in a de re relationship with objects in the world through the non-conceptual information retrieved directly from the objects in the environment. (shrink)

Since Kaplan : 81–98, 1979) first provided a logic for context-sensitive expressions, it has been thought that the only way to construct a logic for indexicals is to restrict it to arguments which take place in a single context— that is, instantaneous arguments, uttered by a single speaker, in a single place, etc. In this paper, I propose a logic which does away with these restrictions, and thus places arguments where they belong, in real world conversations. The central innovation is (...) that validity depends not just on the sentences in the argument, but also on certain abstract relations between contexts. This enrichment of the notion of logical form leads to some seemingly counter-intuitive results: a sequence of sentences may make up a valid argument in one sequence of contexts, and an invalid one in another such sequence. I argue that this is an unavoidable result of context sensitivity in general, and of the nature of indexicals in particular, and that reflection on such examples will lead us to a better understanding of the idea of applying logic to context sensitive expressions, and thus to natural language in general. (shrink)