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.

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

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.

A dynamic semantics for epistemically modalized sentences is an attractive alternative to the orthodox view that our best theory of meaning ascribes to such sentences truth-conditions relative to what is known. This essay demonstrates that a dynamic theory about might and must offers elegant explanations of a range of puzzling observations about epistemic modals. The first part of the story offers a unifying treatment of disputes about epistemic modality and disputes about matters of fact while at the same time avoiding (...) the complexities of alternative theories. The second part of the story extends the basic framework to cover some complicated data about retraction and the interaction between epistemic modality and tense. A comparison between the suggestion made in this essay and current versions of the orthodoxy is provided. (shrink)

This paper develops a compositional, type-driven constraint semantic theory for a fragment of the language of subjective uncertainty. In the particular application explored here, the interpretation function of constraint semantics yields not propositions but constraints on credal states as the semantic values of declarative sentences. Constraints are richer than propositions in that constraints can straightforwardly represent assessments of the probability that the world is one way rather than another. The richness of constraints helps us model communicative acts in essentially the (...) same way that we model agents’ credences. Moreover, supplementing familiar truth-conditional theories of epistemic modals with constraint semantics helps capture contrasts between strong necessity and possibility modals, on the one hand, and weak necessity modals, on the other. (shrink)

This paper presents and discusses a range of counterexamples to the common view that quantifiers cannot take scope over epistemic modals. Some of the counterexamples raise problems for ‘force modifier’ theories of epistemic modals. Some of the counterexamples raise problems for Robert Stalnaker’s theory of counterfactuals, according to which a special kind of epistemic modal must be able to scope over a whole counterfactual. Finally, some of the counterexamples suggest that David Lewis must countenance ‘would’ counterfactuals in which a covert (...) ‘would’ scopes over the whole consequent of the counterfactual, including an overt ‘might.’. (shrink)

In the 1960s, Peter Geach and John Searle independently posed an important objection to the wide class of 'noncognitivist' metaethical views that had at that time been dominant and widely defended for a quarter of a century. The problems raised by that objection have come to be known in the literature as the Frege-Geach Problem, because of Geach's attribution of the objection to Frege's distinction between content and assertoric force, and the problem has since occupied a great deal of the (...) attention both of defenders of broadly noncognitivist views, and of their critics. In this article I explain Geach and Searle's historical objections, and put the subsequent discussion into dialectical context, paying some attention to the developments along the way and how they have enhanced our overall understanding of the problem. The article covers a lot of territory, so we will only be able to see the highlights, along the way. For further reading, see the Works Cited. (shrink)

Expressivists have a problem with negation. The problem is that they have not, to date, been able to explain why ‘murdering is wrong’ and ‘murdering is not wrong’ are inconsistent sentences. In this paper, I explain the nature of the problem, and why the best efforts of Gibbard, Dreier, and Horgan and Timmons don’t solve it. Then I show how to diagnose where the problem comes from, and consequently how it is possible for expressivists to solve it. Expressivists should accept (...) this solution, I argue, because it is demonstrably the only way of avoiding the problem, and because it generalizes. Once we see how to solve the negation problem, I show, it becomes easy to state a constructive, compositional expressivist semantics for a purely normative language with the expressive power of propositional logic, in which we can for the first time give explanatory, formally adequate expressivist accounts of logical inconsistency, logical entailment, and logical validity. As a corollary, I give what I take to be the first real expressivist explanation of why Geach’s original moral modus ponens argument is genuinely logically valid. This proves that the problem with expressivism cannot be that it can’t account for the logical properties of complex normative sentences. But it does not show that the same solution can work for a language with both normative and descriptive predicates, let alone that expressivists are able to deal with more complex linguistic constructions like tense, modals, or even quantifiers. In the final section, I show what kind of constraints the solution offered here would place expressivists under, in answering these further questions. (shrink)

My project in Being For is both constructive and negative. The main aim of the book is to take the core ideas of meta-ethical expressivism as far as they can go, and to try to develop a version of expressivism that solves many of the more straightforward open problems that have faced the view without being squarely confronted. In doing so, I develop an expressivist framework that I call biforcated attitude semantics, which I claim has the minimal structural features required (...) in order to solve some of these open problems facing expressivism. I take biforcated attitude semantics to prove that expressivism is a coherent and interesting hypothesis about the semantics of natural languages.So much for the constructive part; having argued that biforcated attitude semantics incorporates the minimal moves required in order to solve a few of the more pressing open questions facing expressivism, I use it in order to productively constrain what an expressivist answer to further open questions must look like. The results, I end up arguing, are ultimately not promising; the very same structural features that expressivists need in order to answer so simple a problem as to explain why ‘P’ and ‘∼P’ are inconsistent sentences lead to a very general problem about how ordinary, non-moral sentences are to end up with the right truth-conditions, and though I show how to finesse this problem for some simple constructions – truth-conditional connectives and the quantifiers – I ultimately argue that it can’t be done for the full range of constructions in natural languages – including terms like modals, tense and binary quantifiers like ‘most’. So even if expressivism is coherent and interesting, it is an extremely unpromising hypothesis about the language that we actually speak.The main theme of the book is that the most fruitful way …. (shrink)

This paper argues that just as full beliefs can constitute knowledge, so can properties of your credence distribution. The resulting notion of probabilistic knowledge helps us give a natural account of knowledge ascriptions embedding language of subjective uncertainty, and a simple diagnosis of probabilistic analogs of Gettier cases. Just like propositional knowledge, probabilistic knowledge is factive, safe, and sensitive. And it helps us build knowledge-based norms of action without accepting implausible semantic assumptions or endorsing the claim that knowledge is interest-relative.

There are certain uses of and and or that cannot be explained by their normal meanings as truth-functional connectives, even with sophisticated pragmatic resources. These include examples such as The cops show up, and a fight will break out (‘If the cops show up, a fight will break out’), and I have no friends, or I would throw a party (‘I have no friends. If I did have friends, I would throw a party.’). We argue that these uses are indeed (...) distinct from the more ordinary uses of and and or, but that they are nonetheless related in a principled way. To explain them we give an analysis of what we call the dynamic effects of connectives, which arise in all their uses. The special uses at issue are then argued to be instances where the connectives exhibit their dynamic effects without their truth-conditional meaning. (shrink)

"[This book] proposes new foundations for the Bayesian principle of rational action, and goes on to develop a new logic of desirability and probabtility."—Frederic Schick, _Journal of Philosophy_.

Using formal systems to represent and reason about uncertainty.

The semantic theory of expressivism has been applied within metaethics to evaluative words like ‘good’ and ‘wrong’, within epistemology to words like ‘knows’, and within the philosophy of language, to words like ‘true’, to epistemic modals like ‘might’, ‘must’, and ‘probably’, and to indicative conditionals. For each topic, expressivism promises the advantage of giving us the resources to say what sentences involving these words mean by telling us what it is to believe these things, rather than by telling us what (...) it would be for them to be true. This, in turn, absolves these theories of the burden of holding that there is any general answer to what it is for these sentences to be true. However, expressivism is famously subject to a deep and general problem about how to account for the meanings of complex sentences – a problem variously known as the ‘Frege-Geach’ or ‘embedding’ problem. In this paper I will be interested in whether there are reasons to think that the embedding problem looks less difficult for some of these applications for expressivism, than for others. In particular, in this paper I will be interested in the prospects for expressivism about what I will call epistemics – a class which I take to include epistemic modals like ‘might’ and ‘must’, sentential adverbs like ‘probably’, adjectives like ‘likely’ and ‘improbable’, and so-called ‘open’ indicative conditionals like ‘if the Fed doesn’t intervene, then the economy will enter a deflationary spiral’. There are several reasons to be particularly interested in expressivism about epistemics, relating both to the philosophical payoffs of such a view, and relating to the technical prospects for making it work. In other work I’ve touched on the especially interesting philosophical payoffs which make expressivism about epistemics interesting; in this paper I will be interested primarily in evaluating the possibility that there are better prospects for making expressivism about epistemics work than there are for making expressivism work about other topics. There are two main reasons why one might suspect that expressivism about epistemics will have better prospects than expressivism about many other topics, including in metaethics.. (shrink)

This note relates the Lewis/Kratzer view of conditionals as restrictors to the philosophical debate over the meaning of conditionals.

A successful theory of the language of subjective uncertainty would meet several important constraints. First, it would explain how use of the language of subjective uncertainty affects addressees’ states of subjective uncertainty. Second, it would explain how such use affects what possibilities are treated as live for purposes of conversation. Third, it would accommodate 'quantifying in' to the scope of epistemic modals. Fourth, it would explain the norms governing the language of subjective uncertainty, and the differences between them and the (...) norms governing the language of subjective certainty. Neither truth conditional nor traditional force modfier theories of the language of subjective uncertainty look adequate to the task of satisfying all four of these constraints. (shrink)

My dissertation asks how we affect conversational context and how it affects us when we participate in any conversation—including philosophical conversations. Chapter 1 argues that speakers make pragmatic presuppositions when they use proper names. I appeal to these presuppositions in giving a treatment of Frege’s puzzle that is consistent with the claim that coreferential proper names have the same semantic value. I outline an explanation of the way presupposition carrying expressions in general behave in belief ascriptions, and suggest that substitutivity (...) failure is a special case of this behavior. Chapter 2 develops a compositional probabilistic semantics for the language of subjective uncertainty, including epistemic adjectives scoped under quantifiers. I argue that we should distinguish sharply between the effects that epistemically hedged statements have on conversational context, and the effects that they have on belief states. I also suggest that epistemically hedged statements are a kind of doxastic advice, and explain how this hypothesis illuminates some otherwise puzzling phenomena. Chapter 3 argues that ordinary causal talk is deeply sensitive to conversational context. The principle that I formulate to characterize that context sensitivity explains at least some of the oddness of ‘systematic causal overdetermination,’ and explains why some putative overgenerated causes are never felicitously counted, in conversation, as causes. But the principle also makes metaphysical theorizing about causation rather indirectly constrained by ordinary language judgments. (shrink)

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)