The standard semantics for counterfactuals ensures that any counterfactual with a true antecedent and true consequent is itself true. There have been many recent attempts to amend the standard semantics to avoid this result. I show that these proposals invalidate a number of further principles of the standard logic of counterfactuals. The case against the automatic truth of counterfactuals with true components does not extend to these further principles, however, so it is not clear that rejecting the latter should be (...) a consequence of rejecting the former. Instead I consider how one might defuse putative counterexamples to the truth of true-true counterfactuals. (shrink)

I develop a theory of counterfactuals about relative computability, i.e. counterfactuals such as 'If the validity problem were algorithmically decidable, then the halting problem would also be algorithmically decidable,' which is true, and 'If the validity problem were algorithmically decidable, then arithmetical truth would also be algorithmically decidable,' which is false. These counterfactuals are counterpossibles, i.e. they have metaphysically impossible antecedents. They thus pose a challenge to the orthodoxy about counterfactuals, which would treat them as uniformly true. What’s more, I (...) argue that these counterpossibles don’t just appear in the periphery of relative computability theory but instead they play an ineliminable role in the development of the theory. Finally, I present and discuss a model theory for these counterfactuals that is a straightforward extension of the familiar comparative similarity models. (shrink)

A dynamic semantics for iffy oughts offers an attractive alternative to the folklore that Chisholm's paradox enforces an unhappy choice between the intuitive inference rules of factual and deontic detachment. The first part of the story told here shows how a dynamic theory about ifs and oughts gives rise to a nonmonotonic perspective on deontic discourse and reasoning that elegantly removes the air of paradox from Chisholm's puzzle without sacrificing any of the two detachment principles. The second part of the (...) story showcases two bonus applications of the framework suggested here: it offers a response to Forrester's gentle murder paradox and avoids Kolodny and MacFarlane's miners paradox about deontic reasoning under epistemic uncertainty. A comparison between the dynamic semantic proposal made in this paper and a more conservative approach combining a static semantics with a dynamic pragmatics is provided. (shrink)

The debate over Hypothetical Syllogism is locked in stalemate. Although putative natural language counterexamples to Hypothetical Syllogism abound, many philosophers defend Hypothetical Syllogism, arguing that the alleged counterexamples involve an illicit shift in context. The proper lesson to draw from the putative counterexamples, they argue, is that natural language conditionals are context-sensitive conditionals which obey Hypothetical Syllogism. In order to make progress on the issue, I consider and improve upon Morreau’s proof of the invalidity of Hypothetical Syllogism. The improved proof (...) relies upon the semantic claim that conditionals with antecedents irrelevant to the obtaining of an already true consequent are themselves true. Moreover, this semantic insight allows us to provide compelling counterexamples to Hypothetical Syllogism that are resistant to the usual contextualist response. (shrink)

(1988). Explanation, subjunctives and statistical theories. International Studies in the Philosophy of Science: Vol. 3, No. 1, pp. 80-96. doi: 10.1080/02698598808573326.

This discussion note examines a recent argument for the principle that any counterfactual with true components is itself true. That argument rests upon two widely accepted principles of counterfactual logic to which the paper presents counterexamples. The conclusion speculates briefly upon the wider lessons that philosophers should draw from these examples for the semantics of counterfactuals.

This paper provides an update semantics for counterfactual conditionals. It does so by giving a dynamic twist to the ‘Premise Semantics’ for counterfactuals developed in Veltman (1976) and Kratzer (1981). It also offers an alternative solution to the problems with naive Premise Semantics discussed by Angelika Kratzer in ‘Lumps of Thought’ (Kratzer, 1989). Such an alternative is called for given the triviality results presented in Kanazawa et al. (2005, this issue).

Suppose that unobtanium-346 is a rare radioactive isotope. Consider: (1) Every Un346 atom, at its creation, decays within 7 microseconds (µs). (50%) Every Un346 atom, at its creation, has a 50% chance of decaying within 7µs. (1) and (50%) can be true together, but (1) and (50%) cannot together be laws of nature. Indeed, (50%)'s mere (non-vacuous) truth logically precludes (1)'s lawhood. A satisfactory analysis of chance and lawhood should nicely account for this relation. I shall argue first that David (...) Lewis's Humean picture accounts for this relation only by inserting this relation ‘by hand’. Next, I shall argue that this relation between law and chance also threatens a radically non-Humean picture of laws and chances. Finally, I shall offer an account of natural law that nicely explains the relation between chancy facts and deterministic laws. This explanation is not ad hoc because it derives the relation from the very same features of lawhood that account for the laws' special relation to counterfactuals and explain how the laws (unlike the accidents) possess a variety of necessity. The reason that a chancy fact such as (50%) keeps (1) from being a law, without keeping (1) from being true, is ultimately that a chancy fact constrains the subjunctive facts and (1)'s lawhood, unlike (1)'s truth, depends upon the subjunctive facts. (shrink)

A counteridentical is a counterfactual with an identity statement in the antecedent. While counteridenticals generally seem non-trivial, most semantic theories for counterfactuals, when combined with the necessity of identity and distinctness, attribute vacuous truth conditions to such counterfactuals. In light of this, one could try to save the orthodox theories either by appealing to pragmatics or by denying that the antecedents of alleged counteridenticals really contain identity claims. Or one could reject the orthodox theory of counterfactuals in favor of a (...) hyperintensional semantics that accommodates non-trivial counterpossibles. In this paper, I argue that none of these approaches can account for all the peculiar features of counteridenticals. Instead, I propose a modified version of Lewis’s counterpart theory, which rejects the necessity of identity, and show that it can explain all the peculiar features of counteridenticals in a satisfactory way. I conclude by defending the plausibility of contingent identity from objections. (shrink)

This dissertation investigates the ways in which natural language restricts the domains of quantifiers. Adverbs of quantification are analyzed as quantifying over situations. The domain of quantifiers is pragmatically constrained: apparent processes of "semantic partition" are treated as pragmatic epiphenomena. The introductory Chapter 1 sketches some of the background of work on natural language quantification and begins the analysis of adverbial quantification over situations. Chapter 2 develops the central picture of "semantic partition" as a side-effect of pragmatic processes of anaphora (...) resolution. I argue that the apparent effects of topic/focus articulation and presuppositional information on the interpretation of quantifiers are not the result of a direct and local mechanism of sentence grammar. Instead, I develop an analysis where the link is established via the anaphoric dependence of quantifier domains on the discourse context. Chapter 3 discusses the analysis of conditional clauses as quantifier restrictors, concentrating on the question whether conditional clauses restrict quantifiers directly or indirectly. A treatment is explored which has if-clauses constrain the value of the hidden domain variable of the restricted quantifier. Chapter 4, on unless-clauses, and Chapter 5, on only if- and even if-clauses, present some issues in the compositional analysis of complex conditional clauses. These chapters significantly expand the data coverage of the theory of A-quantification. Building on previous work of mine on exceptives, I analyze unless-clauses as exceptive operators on A-quantifiers. The analysis of only if-clauses, treated as conditional clauses that combine if with the focus adverb only, unearthes some interesting new properties. Chapter 6, finally, examines the phenomenon of donkey-anaphora in the light of the results of the previous chapters. I show that a solution to the proportion problem may become possible once we combine the situation-semantic approach to adverbial quantification with the pragmatic theory developed in Chapter 2 and further elaborated in the analysis of donkey anaphora in complex conditionals. (shrink)

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)

Moore's Open Question Arguments are among the most influential arguments in 20th Century metaethical thought. But, surprisingly, there is a fair amount of confusion concerning what the Open Question Arguments actually are, how the Moorean passages should be interpreted, and what they are intended to show. Thus, the early chapters are devoted to clarificatory matters, including the exposing of a variety of contemporary attacks upon Moore's arguments as misguided by indicating where they rest upon faulty interpretations of Moorean passages. Providing (...) what I take to be accurate formulations of Moore's famous arguments, responding to historically important preliminary objections, and, finally, presenting various shortcomings of these arguments constitute the remaining themes of the early chapters. ;Next, I pursue an explanation of what I call the 'Open Question phenomenon': the inclination that many have to endorse Moore's "open question" premises. I survey a variety of popular noncognitivist explanations, arguing that each of them is unsatisfactory. I then present a novel semantic explanation of the phenomenon and use it to construct an augmented Moorean Open Question Argument, one capable of overcoming the shortcomings of Moore's originals. ;The latter chapters are dedicated to an investigation of Moore's preferred normative theory---a version of objective consequentialism. I argue that the standard semantic account of subjunctive conditionals fails to capture the nature of certain subjunctive conditionals relevant to the normative evaluation of alternatives from an objective consequentialist perspective. I then present a modified version of the standard account in an effort to remedy the problem. ;Next, I present a novel objection against all extant versions of objective consequentialism. I then introduce and utilize the concept of an "objective" subjunctive probability in the transformation of a subjective version of consequentialism into an objective version, one capable of dealing with the difficulties posed by the objection. ;I conclude the dissertation with a final chapter in which I defend possibilist versions of consequentialism from a contemporary objection. In doing so, I elucidate a theoretical advantage that possibilist theories have over their subjunctive counterparts. (shrink)

After reviewing several failed arguments that laws cannot change, I use the laws' special relation to counterfactuals to show how temporary laws would have to differ from eternal but time-dependent laws. Then I argue that temporary laws are impossible and that neither Lewis's nor Armstrong's analyses of law nicely accounts for the laws' immutability. *Received September 2006; revised September 2007. ‡Many thanks to John Roberts and John Carroll for valuable comments on earlier drafts, as well as to several anonymous referees (...) for their good suggestions. †To contact the author, please write to: Department of Philosophy, University of North Carolina, CB #3125, Caldwell Hall, Chapel Hill, NC 27599-3125;. (shrink)

I trace the relationship between the view that knowledge is stakes sensitive and Laurie Paul’s account of the epistemology of transformative experience. The view that knowledge is stakes sensitive comes in different flavours: one can go for subjective or objective conceptions of stakes, where subjective views of stakes take stakes to be a function of an agent’s non-factive mental states, and objective views of stakes do not. I argue that there is a tension between subjective accounts of stakes sensitivity and (...) Paul’s epistemology of transformative experience. (shrink)

This article sketches a theory of objective probability focusing on nomic probability, which is supposed to be the kind of probability figuring in statistical laws of nature. The theory is based upon a strengthened probability calculus and some epistemological principles that formulate a precise version of the statistical syllogism. It is shown that from this rather minimal basis it is possible to derive theorems comprising (1) a theory of direct inference, and (2) a theory of induction. The theory of induction (...) is not of the familiar Bayesian variety, but consists of a precise version of the traditional Nicod Principle and its statistical analogues. (shrink)

I argue that there are some causal relata for which it is indeterminate whether one caused the other. Positing indeterminacy in causation helps us defend contested principles in the logic of causation and makes possible new ways of thinking about the theoretical impact of symmetric causal overdetermination. I close by discussing amendments of current theories of causation that would help explain causal indeterminacy.

The aim of this paper is to identify what I take to be the main conceptual problem in Lewis’ semantics for counterfactuals when the Limit Assumption is not satisfied, what I call the Discrimination Problem , and to present and discuss a modification of Lewis’ semantics that aims at solving DP. First, I outline Lewis’ semantics, highlighting the aspects that will be relevant for our discussion. Second, I present DP and discuss it with a heuristic example. Third, I present the (...) new proposal and comment some formal consequences and the objections they give rise to. Fourth, I present an allegedly equivalent version of the proposal and discuss the difference between counterfactuals and strict conditionals. Finally, I defend that the two proposals are different and argue for the first one as the best way of capturing two intuitions that seem in conflict when the LA is not satisfied. I conclude with a dilemma: either the proposal here defended works or LA is inescapable. Thus, if the proposal doe.. (shrink)

Analyses are given of the concepts of absolute and prima facie obligation. The former is a maximizing analysis: roughly, one ought absolutely to perform those actions which are performed in the best worlds accessible to one. The latter analysis is roughly this: one ought prima facie to perform those actions which are such that those accessible worlds in which they are performed are better than the closest accessible worlds in which they are not performed. Accounts of conditional obligation, both absolute (...) and prima facie, are also given, and the issue of the detachment of unconditional from conditional obligation is addressed. (shrink)

Here’s a problem that any reliability theory must face, whether it’s one that holds that beliefs are justified just when they’re products of belief-forming mechanisms with the potential of having good records of yielding true beliefs, or one that holds that a belief meets the standards for knowledge if and only if its causal basis rules out any relevant chance of mistake. The problem is made evident when cast in probabilistic terms. Let r be S’s reason for tokening the true (...) belief that p under conditions c. Then, according to reliabilism, Sis justified in believing that p under c iff r makes it sufficiently probable that p, whileS knows that p iff the conditional probability that p on r and c is unity. But how do we specify the belief context c to be counted as epistemically relevant? As urged recently by John Pollock, on the face of it there seems to be no principled reason for excluding mention of the truth value of the proposition believed. As he says, ‘The only obvious way to construct an objective non-epistemic kind of definite probability is to make it conditional on everything that is true [at the belief’s tokening]’ ; and, as he notes, ‘one feature of the present circumstances is a characterization of the belief as a belief in [p ], and another feature is the truth value of [p]’. But if we allow both the belief token and its truth value membership in the relevant belief context, we then have the hopeless task of explaining how the probability of the token’s being true can be anything but one or zero, one if what is believed is true, and zero if it’s false. This in tum would commit reliabilism to the foolish doctrines that a belief’s truth is sufficient for knowledge, while no false belief is ever even justified. No wonder, then, that Pollock says ‘there is no way to construct an intelligible notion of reliability which does the job required by the reliabilist’. And he is surely right in this: Neither knowledge nor justification can be explained as the chance of a belief’s being true if the relevant belief context is required to mention both the belief tokened and its truth value. We would be engaged in a comparably pointless task were we to try to explain the likelihood of a wager’s being a good bet on a horse race when we had to include among the givens both which horse was picked and its finish, or were we to try to make sense of the assertion that a theory’s predictions have a good chance of being true when both what the theory predicts and its outcome had to be included among the givens. (shrink)