Epistemic modal operators give rise to something very like, but also very unlike, Moore's paradox. I set out the puzzling phenomena, explain why a standard relational semantics for these operators cannot handle them, and recommend an alternative semantics. A pragmatics appropriate to the semantics is developed and interactions between the semantics, the pragmatics, and the definition of consequence are investigated. The semantics is then extended to probability operators. Some problems and prospects for probabilistic representations of content and context are explored.

When I tell you that it’s raining, I describe a way the world is—viz., rainy. I say something whose truth turns on how things are with the weather in the world. Likewise when I tell you that the weatherman thinks that it’s raining. Here the truth of what I say turns on how things are with the weatherman’s state of mind in the world. Likewise when I tell you that I think that it’s raining. Here the truth of what I (...) say turns on how things are with my state of mind in the world. (shrink)

I develop a conception of expressivism according to which it is chiefly a pragmatic thesis about some fragment of discourse, one imposing certain constraints on semantics. The first half of the paper uses credal expressivism about the language of probability as a stalking-horse for this purpose. The second half turns to the question of how one might frame an analogous form of expressivism about the language of deontic modality. Here I offer a preliminary comparison of two expressivist lines. The first, (...) expectation expressivism, looks again to Bayesian modelling for inspiration: it glosses deontically modal language as characteristically serving to express decision-theoretic expectation (expected utility). The second, plan expressivism, develops the idea (due to Gibbard 2003) that this language serves to express 'plan-laden' states of belief. In the process of comparing the views, I show how to incorporate Gibbard's modelling ideas into a compositional semantics for attitudes and modals, filling a lacuna in the account. I close with the question whether and how plan expressivism might be developed with expectation-like structure. (shrink)

This paper defends a counterexample to Modus Tollens, and uses it to draw some conclusions about the logic and semantics of indicative conditionals and probability operators in natural language. Along the way we investigate some of the interactions of these expressions with 'knows', and we call into question the thesis that all knowledge ascriptions have truth-conditions.

This is a study in the meaning of natural language probability operators, sentential operators such as probably and likely. We ask what sort of formal structure is required to model the logic and semantics of these operators. Along the way we investigate their deep connections to indicative conditionals and epistemic modals, probe their scalar structure, observe their sensitivity to contex- tually salient contrasts, and explore some of their scopal idiosyncrasies.

Recently, a number of theorists (MacFarlane (2003, 2011), Egan et al. (2005), Egan (2007), Stephenson (2007a,b)) have argued that an adequate semantics and pragmatics for epistemic modals calls for some technical notion of relativist truth and/or relativist content. Much of this work has relied on an empirical thesis about speaker judgments, namely that competent speakers tend to judge a present-tense bare epistemic possibility claim true only if the prejacent is compatible with their information. Relativists have in particular appealed to judgments (...) elicited in so-called eavesdropping and retraction cases to support this empirical thesis. But opposing theorists have denied the judgments, and at present there is no consensus in the literature about how the speaker judgments in fact pattern. Consequently there is little agreement on what exactly a semantics and pragmatics for epistemic modals should predict about the pattern of judgments in these cases. Further theorizing requires greater clarity on the data to be explained. To clarify the data, we subjected eavesdropping and retraction cases to experimental evaluation. Our data provide evidence against the claim that competent speakers tend to judge a present-tense bare epistemic possibility claim true only if the prejacent is compatible with their information. Theories designed to predict this result are accordingly undermined. (shrink)

There is a longstanding debate in the literature about static versus dynamic approaches to meaning and conversation. A formal result due to van Benthem is often thought to be important for understanding what, conceptually speaking, is at issue in the debate. We introduce the concept of a conversation system, and we use it to clarify the import of van Benthem's result. We then distinguish two classes of conversation systems, corresponding to two concepts of staticness. The first class corresponds to a (...) generalization of the class of systems that van Benthem's result concerns. These are the strongly static conversation systems. The second class is broader, and allows for a certain commonly recognized form of context sensitivity. These are the weakly static conversation systems. In the vein of van Benthem's result, we supply representation theorems which independently characterize these two varieties of conversation system. We observe that some canonically dynamic semantic systems correspond to weakly static conversation systems. We close by discussing some hazards that arise in trying to bring our formal results to bear on natural language phenomena, and on the debate about whether the compositional semantics for natural language should take a dynamic shape. (shrink)

We investigate a basic probabilistic dynamic semantics for a fragment containing conditionals, probability operators, modals, and attitude verbs, with the aim of shedding light on the prospects for adding probabilistic structure to models of the conversational common ground.

Focusing on cases which involve binding into epistemic modals with definite descriptions and quantifiers, I raise some new problems for standard approaches to all of these expressions. The difficulties are resolved in a semantic framework that is dynamic in character. I close with a new class of problems about de re readings within the scope of modals.

This paper critiques a number of standard ways of understanding the role of the metalanguage in a semantic theory for natural language, including the idea that disquotation plays a nontrivial role in any explanatory natural language semantics. It then proposes that the best way to understand the role of a semantic metalanguage involves recognizing that semantics is a model-based science. The metalanguage of semantics is language for articulating features of the theorist's model. Models are understood as mediating instruments---idealized structures used (...) to represent select aspects of the world, aspects the theorist is seeking some theoretical understanding of. The aspect of reality we are seeking some understanding of in semantics is a dimension of human linguistic competence---informally, knowledge of meaning. (shrink)

The view that actually has a reading on which it is a two-dimensional indexical modal operator has some problems.

We distinguish three ways that a theory of linguistic meaning and communication might be considered dynamic in character. We provide some examples of systems which are dynamic in some of these senses but not others. We suggest that separating these notions can help to clarify what is at issue in particular debates about dynamic versus static approaches within natural language semantics and pragmatics.

As Quine observed, the following sentence has a reading which, if true, would be of special interest to the authorities: Ralph believes that someone is a spy. This is the reading where the quantifier is naturally understood as taking wide scope relative to the attitude verb and as binding a variable within the scope of the attitude verb. This essay is interested in addressing the question what the semantic analysis of this kind of reading should look like from a Fregean (...) perspective—a perspective according to which attitude states are generally relations to structured Fregean thoughts composed of senses. The Fregean view faces a challenge of compositionality here. This essay describes the challenge and offers a response on the Fregean's behalf. (shrink)

I respond to comments by David Barnett and Roy Sorensen on my paper ‘Epistemic Modals’.

Consider a language incorporating a mirror-image form of assertion, where the norm is to express what you take to be false rather than what you take to be true. Why aren’t ordinary languages like that? Why do we generally assert what we take to be true rather than what we take to be false? If Lewis and Massey are right, there is a sense in which the question is based on a mistake, and in which English could be described either (...) way. I explore that idea, which centers on the role of duality in language. One of the main questions in the air is whether the symmetry of duality can be used as a guide to ‘real structure’ in semantics and pragmatics. I try to think through it with an analogy to relationism about space. (shrink)

I don’t propose to harp on the question of whether MacFarlane has the data right. Let us just assume, for the sake of argument, that he does. Let us further assume that his interpretation of the data is correct—i.e., that these judgments are assessments of the the whole clause and not simply of the prejacent. Granting all this—maybe a lot—we need a semantics for epistemic modals that will make sense of the judgments in this case, and in relevantly similar cases. (...) Mac- Farlane argues that contextualism about epistemic modals cannot make sense of the judgments. His central worry is that it can only get the truth-value judgments of speakers right by making the truth-conditions of epistemic modal claims outrageously strong—too strong to be assertable in cases where they are, in fact, assertable. We might call it the contextualist’s dilemma: either our semantics systematically fails to capture the truth-value judgments that people actually make, or it captures these judgments but turns users of epistemic modal sentences into irrational asserters. (shrink)