This paper is about the situation in which an author (writer or speaker) presents a deductively invalid argument, but the addressee aims at a charitable interpretation and has reason to assume that the author intends to present a valid argument. How can he go about interpreting the author’s reasoning as enthymematically valid? We suggest replacing the usual find-the-missing-premise approaches by an approach based on systematic efforts to ascribe a belief state to the author against the background of which the argument (...) has to be evaluated. The suggested procedure includes rules for recording whether the author in fact accepts or denies the premises and the conclusion, as well as tests for enthymematic validity and strategies for revising belief state ascriptions. Different degrees of interpretive charity can be exercised. This is one reason why the interpretation or reconstruction of an enthymematic argument typically does not result in a unique outcome. (shrink)

I discuss an argument given by Dorothy Edgington for the conclusion that indicative conditionals cannot express propositions. The argument is not effective against Robert Stalnaker's context-dependent propositional theory. I isolate and defend the feature of Stalnaker's theory that allows it to evade the argument.

I want to model a finite, fallible cognitive agent who imagines that p in the sense of mentally representing a scenario—a configuration of objects and properties—correctly described by p. I propose to capture imagination, so understood, via variably strict world quantifiers, in a modal framework including both possible and so-called impossible worlds. The latter secure lack of classical logical closure for the relevant mental states, while the variability of strictness captures how the agent imports information from actuality in the imagined (...) non-actual scenarios. Imagination turns out to be highly hyperintensional, but not logically anarchic. Section 1 sets the stage and impossible worlds are quickly introduced in Sect. 2. Section 3 proposes to model imagination via variably strict world quantifiers. Section 4 introduces the formal semantics. Section 5 argues that imagination has a minimal mereological structure validating some logical inferences. Section 6 deals with how imagination under-determines the represented contents. Section 7 proposes additional constraints on the semantics, validating further inferences. Section 8 describes some welcome invalidities. Section 9 examines the effects of importing false beliefs into the imagined scenarios. Finally, Sect. 10 hints at possible developments of the theory in the direction of two-dimensional semantics. (shrink)

Let us call a statement of the form ‘If A was, is, or will be the case, then C was, is, or will be the case’ an indicative conditional. And let us call a statement of the form ‘If A had been, were, or were to be the case, then C would have been, would be, or would come to be the case’ a subjunctive, or counterfactual, conditional.

A conditional takes the form ‘If A, then C’. On the truth-conditional view of conditionals, conditional statements state things with truth-conditions. On the suppositional view, conditional statements involve the expression of a supposition. I develop and defend a view on which conditional statements both state things with truth-conditions and express suppositions. On this view, something is fundamentally right about standard truth-conditional and standard suppositional views. Considerations in favor of conditional contents lead us to attribute truth-conditional contents to conditional statements; considerations (...) in favor of the suppositional view then lead us to an unexpected account of these contents. The resulting view has a number of benefits, including a unified treatment of conditional speech acts, a plausible account of our practice of ascribing truth-values to conditional statements, a simple explanation of the apparent equivalence between probabilities of conditionals and conditional probabilities, an intuitive treatment of ‘Gibbardian stand-offs’, a plausible logic of conditionals, and an explanation of why theorizing about conditionals has proved so difficult. (shrink)

The primary aim of this paper is the presentation of a foundation for causal decision theory. This is worth doing because causal decision theory (CDT) is philosophically the most adequate rational decision theory now available. I will not defend that claim here by elaborate comparison of the theory with all its competitors, but by providing the foundation. This puts the theory on an equal footing with competitors for which foundations have already been given. It turns out that it will also (...) produce a reply to the most serious objections made so far against CDT and against the particular version of CDT I will defend. (shrink)

The ontology of decision theory has been subject to considerable debate in the past, and discussion of just how we ought to view decision problems has revealed more than one interesting problem, as well as suggested some novel modifications of classical decision theory. In this paper it will be argued that Bayesian, or evidential, decision-theoretic characterizations of decision situations fail to adequately account for knowledge concerning the causal connections between acts, states, and outcomes in decision situations, and so they are (...) incomplete. Second, it will be argues that when we attempt to incorporate the knowledge of such causal connections into Bayesian decision theory, a substantial technical problem arises for which there is no currently available solution that does not suffer from some damning objection or other. From a broader perspective, this then throws into question the use of decision theory as a model of human or machine planning. (shrink)

Conditionals somehow express conditional beliefs. However, conditional belief is a bi-propositional attitude that is generally not truth-evaluable, in contrast to unconditional belief. Therefore, this article opts for an expressivistic semantics for conditionals, grounds this semantics in the arguably most adequate account of conditional belief, that is, ranking theory, and dismisses probability theory for that purpose, because probabilities cannot represent belief. Various expressive options are then explained in terms of ranking theory, with the intention to set out a general interpretive scheme (...) that is able to account for the most variegated usage of conditionals. The Ramsey test is only the first option. Relevance is another, familiar, but little understood item, which comes in several versions. This article adds a further family of expressive options, which is able to subsume also counterfactuals and causal conditionals, and indicates at the end how this family allows for partial recovery of truth conditions for conditionals. (shrink)

In a series of influential articles, George Bealer argues for the autonomy of philosophical knowledge on the basis that philosophically known truths must be necessary truths. The main point of his argument is that the truths investigated by the sciences are contingent truths to be discovered a posteriori by observation, while the truths of philosophy are necessary truths to be discovered a priori by intuition. The project of assimilating philosophy to the sciences is supposed to be rendered illegitimate by the (...) more or less sharp distinction in these characteristic methods and its modal basis. In this article Bealer's particular way of drawing the distinction between philosophy and science is challenged in a novel manner, and thereby philosophical naturalism is further defended. (shrink)

Systems of logico-probabilistic reasoning characterize inference from conditional assertions that express high conditional probabilities. In this paper we investigate four prominent LP systems, the systems _O, P_, _Z_, and _QC_. These systems differ in the number of inferences they licence _. LP systems that license more inferences enjoy the possible reward of deriving more true and informative conclusions, but with this possible reward comes the risk of drawing more false or uninformative conclusions. In the first part of the paper, we (...) present the four systems and extend each of them by theorems that allow one to compute almost-tight lower-probability-bounds for the conclusion of an inference, given lower-probability-bounds for its premises. In the second part of the paper, we investigate by means of computer simulations which of the four systems provides the best balance of reward versus risk. Our results suggest that system _Z_ offers the best balance. (shrink)

The pattern of credences we are inclined to assign to counterfactuals challenges standard accounts of counterfactuals. In response to this problem, the paper develops a semantics of counterfactuals in terms of the epsilon-operator. The proposed semantics stays close to the standard account: the epsilon-operator substitutes the universal quantifier present in standard semantics by arbitrarily binding the open world-variable. Various applications of the suggested semantics are explored including, in particular, an explanation of how the puzzling credences in counterfactuals come about.

Suppose that all non-qualitative facts are grounded in qualitative facts. I argue that this view naturally comes with a picture in which trans-world identity is indeterminate. But this in turn leads to either pervasive indeterminacy in the non-qualitative, or else contingency in what facts about modality and possible worlds are determinate.

In this paper, it is argued that both the belief state and its input should be represented as epistemic entrenchment (EE) relations. A belief revision operation is constructed that updates a given EE relation to a new one in light of an evidential EE relation, and an axiomatic characterization of this operation is given. Unlike most belief revision operations, the one developed here can handle both multiple belief revision and iterated belief revision.

This article begins by outlining some of the history—beginning with brief remarks of Quine's—of work on conditional assertions and conditional events. The upshot of the historical narrative is that diverse works from various starting points have circled around a nexus of ideas without convincingly tying them together. Section 3 shows how ideas contained in a neglected article of de Finetti's lead to a unified treatment of the topics based on the identification of conditional events as the objects of conditional bets. (...) The penultimate section explores some of the consequences of the resulting logic of conditional events while the last defends it. (shrink)

It is widely held that counterfactuals, unlike attitude ascriptions, preserve the referential transparency of their constituents, i.e., that counterfactuals validate the substitution of identicals when their constituents do. The only putative counterexamples in the literature come from counterpossibles, i.e., counterfactuals with impossible antecedents. Advocates of counterpossibilism, i.e., the view that counterpossibles are not all vacuous, argue that counterpossibles can generate referential opacity. But in order to explain why most substitution inferences into counterfactuals seem valid, counterpossibilists also often maintain that counterfactuals (...) with possible antecedents are transparency‐preserving. I argue that if counterpossibles can generate opacity, then so can ordinary counterfactuals with possible antecedents. Utilizing an analogy between counterfactuals and attitude ascriptions, I provide a counterpossibilist‐friendly explanation for the apparent validity of substitution inferences into counterfactuals. I conclude by suggesting that the debate over counterpossibles is closely tied to questions concerning the extent to which counterfactuals are more like attitude ascriptions and epistemic operators than previously recognized. (shrink)

Higginbotham (1986) observed that quantified conditionals have a stronger meaning than might be expected, as attested by the apparent equivalence of examples like No student will pass if he goofs off and Every student will fail if he goofs off. Higginbotham's observation follows straightforwardly given the validity of conditional excluded middle (CEM; as observed by von Fintel & Iatridou 2002), and as such could be taken as evidence thereof (e.g. Williams forthcoming). However, the empirical status of CEM has been disputed, (...) and it is invalid under many prominent theories of conditionals—notably Lewis (1973) for counterfactuals, also Kratzer (1979, 1991). More acutely, Higginbotham's observation holds even for quantified counterparts of conditionals that appear not to obey CEM (Higginbotham 2003), and the standard way of explaining (away) such apparent counterexamples to the principle, à la Stalnaker (1981), does not directly yield an account of our apparent truth-conditional intuitions about the quantified counterparts (Leslie 2009). This article provides an explanation for the latter intuitions within Stalnaker's framework, the upshot being that CEM does remain a viable explanation, in principle, for Higginbotham's observation. (shrink)

Disjunctive antecedent conditionals —conditionals of the form if A or B, C—sometimes seem to entail both of their simplifications and sometimes seem not to. I argue that this behavior reveals a genuine ambiguity in DACs. Along the way, I discuss a new observation about the role of focal stress in distinguishing the two interpretations of DACs. I propose a new theory, according to which the surface form of a DAC underdetermines its logical form: on one possible logical form, if A (...) or B, C does entail both of its simplifications, while on the other, it does not. (shrink)

The problem of the source of necessity is the problem of explaining what makes necessary truths necessarily true. Simon Blackburn has presented a dilemma intended to show that any reductive, realist account of the source of necessity is bound to fail. Although Blackburn's dilemma faces serious problems, reflection on the form of explanations of necessities reveals that a revised dilemma succeeds in defeating any reductive account of the source of necessity. The lesson is that necessity is metaphysically primitive and irreducible.

Summary of Anna Pilatova’s doctoral thesis A User’s Guide to Proper Names, Their Semantics And Pragmatics The origins of this work go all the way back to my reading of Kripke’s Naming and Necessity in 1993. It had left me with a feeling of dissatisfaction that lingered long enough to inspire my MA thesis (on Internalism and Externalism in the Theories of Reference), and finally inspired the current work. Over time, I became acquainted with other influential accounts of reference of (...) proper names, but my unease with essentialism and wariness of direct designation remained. In the User’s Guide to Proper Names, I seized the opportunity to analyse what I thought was problematic with the mainstream theories of reference of proper names. I tried to tease apart a number of related doctrines about the behaviour of proper names, and thus arrive at a better understanding of how the various parts of the theories of reference I chose to analyse are related. This helped me to develop my own proposal regarding both the semantics and the pragmatics of proper names. The Guide is organised around a particular approach to the tasks of a semantic theory. According to this view, proposed by Stalnaker, a semantic theory dealing with proper names should account for the descriptive semantics of names, their foundational semantics, and the semantics of modal statements in which they figure. Descriptive semantics focuses on the contribution a proper name makes to the truth-value of sentences in which it occurs. Based on such an analysis, a proper name is assigned a semantic value, which is supposed to provide us with an interpretation of that name. A crucial part of this task is to see just what kind of thing the semantic value of a proper name is. In interpreting sentences containing proper names, one can, and often does, use the notion of possible worlds. This is especially true if the sentences in question are modal. There are various approaches to modality, which carry with them different sets of presuppositions. An analysis of the systematic features and presuppositions of various possible-world frameworks is a part of the task of the semantics of modal statements. Another task of semantics of modal statements is to investigate whence the constraints on possible worlds used in analysing these statements should derive, that is, whether, and to what degree, they should derive from the descriptive or the foundational part of the semantic enterprise. Both of these parts of a semantic theory have the potential to make predictions about the foundational semantics of proper names, which deals with the speaker’s behaviour and communication. Foundational semantics aims at answering the following question: What makes it the case that the language spoken by a particular individual or community has the very descriptive semantics it has? In this investigation, one looks at the speaker, her intentions and communicative goals, and tries to look at the strategies she uses to get her (linguistic) point across. To show the usefulness of organising the User’s Guide to Proper Names around these distinctions, and to provide their proper characterisation, is the task of the first part of the introductory first chapter, Outlining the Field and Introducing Some of the Players. In the second part of the same chapter, Setting the Scene, I give a preliminary outline of some of the notions needed to describe the theories of reference that are later investigated, that is mainly the theories proposed by Kripke, Kaplan, Lewis, and Stalnaker. The second chapter, Descriptive Semantics, focuses on the descriptive semantics proposed by Kripke and Kaplan for proper names. In the first part of the chapter, I introduce several arguments in favour of rigid designation. A closer look reveals that none of the three arguments in question -- the modal, the epistemological, and the semantic one -- is actually an argument for rigid designation. They all just argue against some forms of descriptivism. Moreover, in the case of the modal and the epistemological argument, it is relatively easy to find forms of descriptivism that are immune to the lines of reasoning proposed in these arguments. The semantic argument seems to be the strongest of the three. An analysis of a direct argument for rigid designation highlights the connection between rigid designation and certain preconceptions about the identity of individuals. A further investigation of the notion of identity of individuals across possible worlds emerges at this point as an important issue to tackle. It also becomes clear that rigid designation alone cannot fully determine the Kripkean picture of names as non-descriptive entities referring without a mediation of any sort of conceptual content. In the second part of Chapter 2, I introduce the basic notions of Kaplan’s approach to the descriptive semantics of proper names. It turns out that in order to derive the familiar Kripkean picture of proper names, one has to presuppose direct reference for names and at least some version of haecceitism for the individuals in question. While, as we show, Kaplan’s framework does not work well for proper names, it gives us conceptual tools that help us in our undertaking. In the third chapter, Modal Statements, Individuals, and Essences, I analyse three different approaches to building a possible-world framework, Lewis’s, Kripke’s, and Stalnaker’s. In each case, the same questions are asked: What is the motivation and intended field of application of this framework? What are the ontological commitments of the approach? What form of essentialism, if any, does it imply? How does it deal with the notion of an individual? In Lewis’s case, the main problem turns out to be the theory of counterparts, which is, as I show, an integral part of his approach. The concept of an individual implied by it does not seem to correspond to any intuitive reading of counterfactual statements involving individuals. The investigation of Kripke’s framework focuses on describing the weakest form of essentialism that has to be presupposed to make the proposal work. Once that is concluded, I analyse the essentialism Kripke actually proposes, and the motivation and presuppositions on which it rests. I conclude that its motivation cannot be said to come from an analysis of language and that it presupposes a particular form of scientific realism. The rest of the chapter is devoted to a reconstruction and analysis of Stalnaker’s possible world framework, which turns out to be rather more cautious about metaphysical presuppositions and more suited for an analysis of natural language. As in the two previous proposals, I try to reconstruct the notion of actual world that is presupposed here. In the fourth chapter, Foundational Semantics, I investigate the notion of proposition implied by Lewis’s, Kripke’s, and Stalnaker’s approach. I focus on propositions containing proper names, and analyse the way in which each of the conceptions mentioned above is vulnerable to the problem of logical omniscience. An analysis of Lewis’s framework reveals that the concept of proposition implied by it is so weak as to be rather uninteresting. An investigation of Kripke’s concept of proposition deals not only with the systematic issues, but also with the Pierre puzzle and various attempts at solving it. I present a number of different approaches to the problem and compare their merits. Stalnaker is very worried about the problem of logical omniscience, and yet it turns out that his conception is less vulnerable to the adverse consequences of the problem of logical omniscience than other frameworks we investigate. I point out that various pragmatic features of Stalnaker’s framework (the epistemic nature of his possible-world framework, the Gricean principles built into the notion of assertion) help to counterbalance and mitigate the scope of the problem of logical omniscience within it. In Chapter 5, User-friendly Descriptive Semantics, I present and motivate my own proposal for the descriptive semantics of proper names and the treatment of modal statements in which they figure. Basically, the aim is to preserve the notion of names as rigidly designating expressions while admitting as little metaphysics as possible. Working with epistemic possible worlds whose domain is in each case co-determined by a particular context enables me to develop a very intuitive plausible notion of individual, to which a name can be said to refer rigidly. The interpretation of modal statements is then driven not by essentialist constraints in the common sense of the term, but by context-derived limitations, which seems to be a more natural approach. In the sixth and last chapter, Names, Indexicality, and Ambiguity, I develop a view of foundational semantics inspired by the pragmatic observation that in common parlance one can say that a name, `John Smith’ for instance, can refer to numerous individuals. A lot of attention is given to the ontology of names, and the question `What is a name?’ delivers answers which are then used in a discussion about whether names should be seen as indexical or ambiguous. I adopt the ambiguity view, and propose a way of using a Stalnakerian possible-world framework to derive intuitively plausible results for some difficult cases. The weight of the discussion all through the guide rests in an examination of different kinds of presuppositions implied by various possible-world frameworks and the notion of the individual used in accounts of the behaviour of proper names. In my own account of these issues, I do without any metaphysical assumptions and aim at describing communication in terms accessible to its participants. (shrink)

This thesis consists of an introduction and five essays on decision theory.