Possible-World Theories of Counterfactuals

We develop and defend a new approach to counterlogicals. Non-vacuous counterlogicals, we argue, fall within a broader class of counterfactuals known as counterconventionals. Existing semantics for counterconventionals (developed by Einheuser (2006) and Kocurek et al. (2020)) allow counterfactuals to shift the interpretation of predicates and relations. We extend these theories to counterlogicals by allowing counterfactuals to shift the interpretation of logical vocabulary. This yields an elegant semantics for counterlogicals that avoids problems with the usual impossible worlds semantics. We conclude by (...) showing how this approach can be extended to counterpossibles more generally. (shrink)

Brogaard and Salerno (2008) argued that counter-examples to contraposition, strengthening the antecedent, and hypothetical syllogism involving subjunctive conditionals only seem to work because they involve a contextual fallacy where the context assumed in the premise(s) is illicitly shifted in the conclusion. To avoid such counter-examples they have proposed that the context must remain fixed when evaluating an argument for validity. That is the Brogaard-Salerno Stricture. Tristan Haze (2016), however, has recently objected that intuitively valid argumentative forms such as conjunction introduction (...) do not satisfy this constraint. This paper has two goals. First, it argues that the Brogaard-Salerno Stricture is not violated in Haze’s putative counter-example. Second, it argues that since this stricture blocks the usual counter-examples to instances of classical argumentative forms that involve indicative or subjunctive conditionals, it is reasonable to infer that indicative and subjunctive conditionals are material. (shrink)

According to an increasingly popular view among philosophers of science, both causal and non-causal explanations can be accounted for by a single theory: the counterfactual theory of explanation. A kind of non-causal explanation that has gained much attention recently but that this theory seems unable to account for are grounding explanations. Reutlinger (2017) has argued that, despite these appearances to the contrary, such explanations are covered by his version of the counterfactual theory. His idea is supported by recent work on (...) grounding by Schaffer and Wilson who claim there to be a tight connection between grounding and counterfactual dependence. The present paper evaluates the prospects of the idea. We show that there is only a weak sense in which grounding explanations convey information about counterfactual dependencies, and that this fact cannot plausibly be taken to reveal a distinctive feature that grounding explanations share with other kinds of explanations. (shrink)

Causal models provide a framework for making counterfactual predictions, making them useful for evaluating the truth conditions of counterfactual sentences. However, current causal models for counterfactual semantics face logical limitations compared to the alternative similarity-based approaches: they only apply to a limited subset of counterfactuals and the connection to counterfactual logic is not straightforward. This paper offers a causal framework for the semantics of counterfactuals which improves upon these logical issues. It extends the causal approach to counterfactuals to handle more (...) complex counterfactuals, including backtracking counterfactuals and those with logically complex antecedents. It also uses the notion of causal worlds to define a selection function and shows that this selection function satisfies familiar logical properties. While some limitations still arise, especially regarding counterfactuals which require breaking the laws of the causal model, this model improves upon many of the existing logical limitations of causal models. (shrink)

The apparent consistency of Sobel sequences (example below) famously motivated David Lewis to defend a variably strict conditional semantics for counterfactuals. (a) If Sophie had gone to the parade she would have seen Pedro. (b) If Sophie had gone to the parade and been stuck behind someone tall she would not have seen Pedro. But if the order of the counterfactuals in a Sobel sequence is reversed – in the example, if (b) is asserted prior to (a) – the second (...) counterfactual asserted no longer rings true. This is the Heim sequence problem. That the order of assertion makes this difference is surprising on the variably strict account. Some argue that this is reason to reject the Lewis-Stalnaker semantics outright. Others argue that the problem motivates a contextualist rendering of counterfactuals. Still others maintain that the explanation for the phenomenon is merely pragmatic. I argue that none of these are right, and defend a novel way to understand the phenomenon. My proposal avoids the problems faced by the alternative analyses and enjoys independent support. There is, however, a difficulty for my view: it entails that many ordinarily-accepted counterfactuals are not true. I argue that this (apparent) cost is acceptable. (shrink)

How do generics interact with modals? This note offers one observation about an interaction with 'might' that presents a challenge for standard theories.

The principle of Conditional Excluded Middle has been a matter of longstanding controversy in both semantics and metaphysics. According to this principle, we are, inter alia, committed to claims like the following: If the coin had been flipped, it would have landed heads, or if the coin had been flipped, it would not have landed heads. In favour of the principle, theorists have appealed, primarily, to linguistic data such as that we tend to hear ¬(A > B) as equivalent to (...) (A > ¬B). Williams (2010), provides one of the most compelling recent arguments along these lines by appealing to intuitive equivalencies between certain quantified conditional statements. We argue that the strategy Williams employs can be parodied to generate an argument for the unwelcome principle of Should Excluded Middle: the principle that, for any A, it either should be that A or it should be that not A. Uncovering what goes wrong with this argument casts doubt on a key premise in Williams’ argument. The way we develop this point is by defending the thesis that, like "should", "would" is a so-called neg-raising predicate. Neg-raising is the linguistic phenomenon whereby “I don’t think that Trump is a good president” strongly tends to implicate “I think that Trump is not a good president,” despite the former not semantically entailing the latter. We show how a defender of a Lewis-style semantics for counterfactuals should implement the idea that the counterfactual is a “neg-raiser”. (shrink)

La logica modale è nata per studiare i ragionamenti su ciò che è possibile e ciò che è necessario. Negli ultimi decenni, a partire dal lavoro di logici e filosofi quali Rudolf Carnap, Saul Kripke e David Lewis, la sua applicazione è stata progressivamente estesa ad altri ambiti, quali il ragionamento sul tempo, sulla conoscenza e sui sistemi di norme. Queste ricerche hanno condotto a un complesso e intrigante dialogo con alcune fondamentali branche della filosofia: la metafisica, l’epistemologia, la filosofia (...) del linguaggio. Lo scopo del volume è offrire una panoramica di questo dialogo al contempo accessibile e rigorosa, pensata sia per gli studenti di un corso universitario, sia per il lettore non specialista. Se da un lato tutte le necessarie nozioni tecniche sono rese accessibili ai non addetti ai lavori, dall'altro si restituisce un'immagine fedele delle sfide concettuali che la ricerca in questi settori è oggi chiamata ad affrontare. (shrink)

Slavery harmed the slaves but not their descendants since slavery brought about their existence. The descendants gain the slaves’ claims via inheritance. However, collecting the inheritance-based claim runs into a number of difficulties. First, every descendant usually has no more than a portion of the slave’s claim because the claim is often divided over generations. Second, there are epistemic difficulties involving the ownership of the claim since it is unlikely that a descendant of a slave several generations removed would have (...) retained the claim of inheritance given the loss of wealth and disinheritance that often characterizes families. There are also problems in determining the amount of inheritance. This is in part because of the problems of calculating in the effects of offsets, especially crime-related offsets, which are owed by a significant portion of the descendants. Even if this inheritance claim can be established with sufficient confidence certain entities may not be asked to pay it. The federal government does not owe compensation since as a historical matter it permitted but did not cause enslavement. The beneficiaries of slavery do not owe compensation since merely receiving the benefit of an unjust activity does not by itself generate a debt of compensation. When combined these problems constitute an overwhelming case against reparations. (shrink)

There is long standing agreement both among philosophers and linguists that the term ‘counterfactual conditional’ is misleading if not a misnomer. Speakers of both non-past subjunctive (or ‘would’) conditionals and past subjunctive (or ‘would have’) conditionals need not convey counterfactuality. The relationship between the conditionals in question and the counterfactuality of their antecedents is thus not one of presupposing. It is one of conversationally implicating. This paper provides a thorough examination of the arguments against the presupposition view as applied to (...) past subjunctive conditionals and finds none of them conclusive. All the relevant linguistic data, it is shown, are compatible with the assumption that past subjunctive conditionals presuppose the falsity of their antecedents. This finding is not only interesting on its own. It is of vital importance both to whether we should consider antecedent counterfactuality to be part of the conventional meaning of the conditionals in question and to whether there is a deep difference between indicative and subjective conditionals. (shrink)

In a recent paper, Pruss (2013) proves the validity of the rule beta-2 relative to Lewis’s semantics for counterfactuals, which is a significant step forward in the debate about the consequence argument. Yet, we believe there remain intuitive counter-examples to beta-2 formulated with the actuality operator and rigidified descriptions. We offer a novel and two-dimensional formulation of the Lewisian semantics for coun- terfactuals and prove the validity of a new transfer rule according to which a new version of the consequence (...) argument can be formulated. This new transfer rule is immune to the counter-examples involving the actuality operator and rigidified descriptions. However, we show that counter-examples to this new rule can also be generated, demanding that the Lewisian semantics be generalized for higher dimensions where counter-examples can always be generated. (shrink)

The material account claims that indicative conditionals are material. However, the conventional wisdom even among material account enthusiasts is that the material account cannot be extended to subjunctive conditionals. There are mainly three reasons that motivate this consensus: (1) the belief that if subjunctives were material, most subjunctive conditionals would be vacuously true, which is implausible; (2) its inconsistency with Adam pairs, which suggest that indicative and subjunctive conditionals have different truth conditions; and (3) the belief that it is an (...) inferior hypothesis compared to the possible world theories. I will argue against (1) that the counterintuitive aspects of vacuously true conditionals can be explained away in a uniform fashion, regardless of whether they are indicatives or subjunctives. I reinforce this assumption by showing that the positive arguments for the material account of indicatives are also intuitively valid for subjunctives. The point mentioned in (2) is resisted by explaining Adam pairs as logically equivalent conditionals that can be appropriate at different times, depending of the speaker’s epistemic situation. Finally, (3) is criticised by making the case that the possible world account faces insurmountable problems and that a full-blown material account of indicatives and subjunctives is overall a more elegant solution. (shrink)

There are two leading theories about the meaning of counterfactuals, the Variably Strict Analysis (VSA) and the Strict Analysis (SA). Perhaps most famously, VSA and SA disagree about a principle known as Antecedent Strengtheing: SA validates the principle; VSA does not. Early VSA theorists believed that certain apparent counterexamples to Antecedent Strengthening— now known as Sobel Sequences—refuted SA. More recently, defenders of SA have enriched SA with certain dynamic principles governing how context evolves and argued that Sobel sequences are not (...) counterexamples to the resulting Dynamic SA. -/- But Antecedent Strengthening is just one of a family of strengthening principles. In this paper, we focus on a weaker principle, which we call Strengthening with a Possibility, and give a counterexample to it. We show that the dynamic features attributed to would-counterfactuals and might-counterfactuals by proponents Dynamic SA are of no help when it comes to counterexamples to Strengthening with a Possibility, unlike counterexamples to Antecedent Strengthening itself. We develop a new version of VSA that incorporates a Kratzerian ordering source into the meaning of counterfactuals, and we show how to model counterexamples to Strengthening with a Possibility on our account. (shrink)

A great deal has been written about 'would' counterfactuals of causal dependence. Comparatively little has been said regarding 'would' counterfactuals of ontological dependence. The standard Lewis-Stalnaker semantics is inadequate for handling such counterfactuals. That's because some of these counterfactuals are counterpossibles, and the standard Lewis-Stalnaker semantics trivializes for counterpossibles. Fortunately, there is a straightforward extension of the Lewis-Stalnaker semantics available that handles counterpossibles: simply take Lewis's closeness relation that orders possible worlds and unleash it across impossible worlds. To apply the (...) extended semantics, an account of the closeness relation for counterpossibles is needed. In this paper I offer a strategy for evaluating 'would' counterfactuals of ontological dependence that understands closeness between worlds in terms of the metaphysical concept of grounding. (shrink)

I present data that suggest the universal entailments of counterfactual donkey sentences aren’t as universal as some have claimed. I argue that this favors the strategy of attributing these entailments to a special property of the similarity ordering on worlds provided by some contexts, rather than to a semantically encoded sensitivity to assignment.

Our understanding of subjunctive conditionals has been greatly enhanced through the use of possible world semantics and, more precisely, by the idea that they involve variably strict quantification over possible worlds. I propose to extend this treatment to ceteris paribus conditionals – that is, conditionals that incorporate a ceteris paribus or ‘other things being equal’ clause. Although such conditionals are commonly invoked in scientific theorising, they traditionally arouse suspicion and apprehensiveness amongst philosophers. By treating ceteris paribus conditionals as a species (...) of variably strict conditional I hope to shed new light upon their content and their logic. (shrink)

The Identity principle says that conditionals with the form 'If p, then p' are logical truths. Identity is overwhelmingly plausible, and has rarely been explicitly challenged. But a wide range of conditionals nonetheless invalidate it. I explain the problem, and argue that the culprit is the principle known as Import-Export, which we must thus reject. I then explore how we can reject Import-Export in a way that still makes sense of the intuitions that support it, arguing that the differences between (...) indicative and subjunctive conditionals play a key role in solving this puzzle. (shrink)

This note identifies and corrects some problems in developments of the thesis that predictive expressions, such as English "will", are modals. I contribute a new argument supporting Cariani and Santorio's recent claim that predictive expressions are non-quantificational modals. At the same time, I improve on their selectional semantics by fixing an important bug. Finally, I show that there are benefits to be reaped by integrating the selection semantics framework with standard ideas about the future orientation of modals.

Aaccording to D. K. lewis (1973), would-couterfactuals and might-counterfactuals are duals. from this, it follows that the negation of a would-counterfactual is equiv- alent to the corresponding “might-not”-counterfactual and that the negation of a might-counterfactual is equivalent to the corresponding “would-not”- counterfactual. there are cases, however, where we seem to be entitled to accept the would- counterfactual and we are also equally entitled to accept the corresponding might-not-counterfactual and cases where we seem to be entitled to accept the might-counterfactual without (...) being equally entitled to reject the corresponding would-not-counterfactual. In this paper, I will show that a distinction between two types of rejections for counterfactuals (p-rejection and s-rejection) and the recognition that might-not-counterfactuals may play the role of p-rejections (by an application to counterfactuals of the lewisian approach to conversational scores) could explain why the problematic cases should not be seen as cases where the duality of would- and might-counterfactuals fails. (shrink)

von Fintel and Gillies : 329–360, 2007) have proposed a dynamic strict conditional account of counterfactuals as an alternative to the standard variably strict account due to Stalnaker and Lewis. Von Fintel’s view is motivated largely by so-called reverse Sobel sequences, about which the standard view seems to make the wrong predictions. More recently Moss :561–586, 2012) has offered a pragmatic/epistemic explanation that purports to explain the data without requiring abandonment of the standard view. So far the small amount of (...) subsequent literature has focused primarily on the original class of cases motivating the strict conditional view. What is needed in the debate is an examination of the predictions of the dynamic strict conditional account for a broader range of data. I undertake this task here, presenting a slew of cases that are problematic for the strict conditional view but not for Moss’s view, and considering some possible responses. Ultimately I take my contribution to constitute a significant blow to the dynamic strict conditional view, though not a decisive verdict against it. (shrink)

Several theorists have been attracted to the idea that in order to account for counterpossibles, i.e. counterfactuals with impossible antecedents, we must appeal to impossible worlds. However, few have attempted to provide a detailed impossible worlds account of counterpossibles. Berit Brogaard and Joe Salerno’s ‘Remarks on Counterpossibles’ is one of the few attempts to fill in this theoretical gap. In this article, I critically examine their account. I prove a number of unanticipated implications of their account that end up implying (...) a counterintuitive result. I then examine a suggested revision and point out a surprising implication of the revision. (shrink)

A standing challenge in the theory of counterfactuals is to solve the “deviation problem”. Consider ordinary counterfactuals involving an antecedent concerning a difference from the actual course of events at a particular time, and a consequent concerning, at least in part, what happens at a later time. In the possible worlds framework, the problem is often put in terms of which are the relevant antecedent worlds. Desiderata for the solution include that the relevant antecedent worlds be governed by the actual (...) laws of nature with no miracles; that the past in those worlds before the antecedent time matches the actual past; that the account is compatible with determinism, and that many of our ordinary counterfactual judgments are correct, and would be correct even given determinism. Many theorists have compromised on one or more of these desiderata, but this paper presents an account employing impossible worlds that satisfies them all. (shrink)

Based on a crowdsourced truth value judgment experiment, we provide empirical evidence challenging two classical views in semantics, and we develop a novel account of counterfactuals that combines ideas from inquisitive semantics and causal reasoning. First, we show that two truth-conditionally equivalent clauses can make different semantic contributions when embedded in a counterfactual antecedent. Assuming compositionality, this means that the meaning of these clauses is not fully determined by their truth conditions. This finding has a clear explanation in inquisitive semantics: (...) truth-conditionally equivalent clauses may be associated with different propositional alternatives, each of which counts as a separate counterfactual assumption. Second, we show that our results contradict the common idea that the interpretation of a counterfactual involves minimizing change with respect to the actual state of affairs. We propose to replace the idea of minimal change by a distinction between foreground and background for a given counterfactual assumption: the background is held fixed in the counterfactual situation, while the foreground can be varied without any minimality constraint. (shrink)

A part of Stalnaker (1968)’s influential theory of conditionals has been neglected, namely the role for an accessibility relation between worlds. I argue that the accessibility relation does not play the role intended for it in the theory as stated, and propose a minimal revision which solves the problem, and brings the theory in line with the formulation in Stalnaker & Thomason 1970.

Language theorists have recently come to have an increasing appreciation for the fact that context contributes heavily in determining our interpretation of what is said. Indeed, it now seems clear that no complete understanding of a natural language is possible without some account of the way in which context affects our interpretation of discourse. In this paper, I will attempt to explore one facet of the language – context relationship, namely, the relation between conditionals and context. The first part of (...) the paper develops an account of truth for conditionals which allows them to depend on momentary features of the context in which they are uttered. In the second half of the paper, comparisons with other recent theories of the conditional will be considered. Particular attention will be given to the problem of whether the conditional really violates classical inferences such as Hypothetical Syllogism and Contraposition as has often been claimed in recent years. (shrink)

Several theists, including Linda Zagzebski, have claimed that theism is somehow committed to nonvacuism about counterpossibles. Even though Zagzebski herself has rejected vacuism, she has offered an argument in favour of it, which Edward Wierenga has defended as providing strong support for vacuism that is independent of the orthodox semantics for counterfactuals, mainly developed by David Lewis and Robert Stalnaker. In this paper I show that argument to be sound only relative to the orthodox semantics, which entails vacuism, and give (...) an example of a semantics for counterfactuals countenancing impossible worlds for which it fails. (shrink)

Sobel sequences have had a huge impact on the discussion of counterfactuals. They can be composed of conditionals and mere descriptions. What is especially puzzling about them is that they are often felicitously uttered when their reversal is not. Up to now, there is no unified explanation. I examine two strategies. We might begin with conditionals and proceed to descriptions. Or we might begin with descriptions and proceed to conditionals. I argue for the latter variant and outline a universal theory (...) of Sobel sequences in terms of presuppositional anaphora. One relevant result is that the phenomenon neither counts against nor in favour of the simplified standard account of counterfactuals à la Stalnaker-Lewis. (shrink)

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)

One well-known objection to the traditional Lewis-Stalnaker semantics of counterfactuals is that it delivers counterintuitive semantic verdicts for many counterpossibles (counterfactuals with necessarily false antecedents). To remedy this problem, several authors have proposed extending the set of possible worlds by impossible worlds at which necessary falsehoods may be true. Linguistic ersatz theorists often construe impossible worlds as maximal, inconsistent sets of sentences in some sufficiently expressive language. However, in a recent paper, Bjerring (2014) argues that the “extended” Lewis-Stalnaker semantics delivers (...) the wrong truth-values for many counterpossibles if impossible worlds are required to be maximal. To make room for non-maximal or partial impossible worlds, Bjerring considers two alternative world-ontologies: either (i) we construe impossible worlds as arbitrary (maximal or partial) inconsistent sets of sentences, or (ii) we construe them as (maximal or partial) inconsistent sets of sentences that are closed and consistent with respect to some non-classical logic. Bjerring raises an objection against (i), and suggests that we opt for (ii). In this paper, I argue, first, that Bjerring’s objection against (i) conflates two different conceptions of what it means for a logic to be true at a world. Second, I argue that (ii) imposes too strong constraints on what counts as an impossible world. I conclude that linguistic ersatzists should construe impossible worlds as arbitrary (maximal or partial) inconsistent sets of sentences. (shrink)

I consider a puzzling case presented by Jose Benardete, and by appeal to this case develop a paradox involving counterfactual conditionals. I then show that this paradox may be leveraged to argue for certain non-obvious claims concerning the logic of counterfactuals.

http://alexanthony.org/dispositions%20and%20modality.pdf.

The main goal of this paper is to investigate the relation between the meaning of a sentence and its truth conditions. We report on a comprehension experiment on counterfactual conditionals, based on a context in which a light is controlled by two switches. Our main finding is that the truth-conditionally equivalent clauses (i) "switch A or switch B is down" and (ii) "switch A and switch B are not both up" make different semantic contributions when embedded in a conditional antecedent. (...) Assuming compositionality, this means that (i) and (ii) differ in meaning, which implies that the meaning of a sentential clause cannot be identified with its truth conditions. We show that our data have a clear explanation in inquisitive semantics: in a conditional antecedent, (i) introduces two distinct assumptions, while (ii) introduces only one. Independently of the complications stemming from disjunctive antecedents, our results also challenge analyses of counterfactuals in terms of minimal change from the actual state of affairs: we show that such analyses cannot account for our findings, regardless of what changes are considered minimal. (shrink)

Peter van Inwagen famously offers a version of the luck objection to libertarianism called the ‘Rollback Argument.’ It involves a thought experiment in which God repeatedly rolls time backward to provide an agent with many opportunities to act in the same circumstance. Because the agent has the kind of freedom that affords her alternative possibilities at the moment of choice, she performs different actions in some of these opportunities. The upshot is that whichever action she performs in the actual-sequence is (...) intuitively a matter of mere chance. I explore a new response to the Rollback Argument. If there are true counterfactuals of libertarian freedom, then the agent performs the same action each time she is placed in the same circumstance, because that is what she would freely do in that circumstance. This response appears to negate the chancy intuition. Ultimately, however, I argue that this new response is unsuccessful, because there is a variant of the Rollback Argument that presents the same basic challenge to the libertarian on the assumption that there are true counterfactuals of libertarian freedom. Thus, true counterfactuals of libertarian freedom do not provide the libertarian with a solution to the Rollback Argument. (shrink)

Stalnaker argued that conditional excluded middle should be included in the principles that govern counterfactuals on the basis that intuitions support that principle. This is because there are pairs of competing counterfactuals that appear to be equally acceptable. In doing so, he was forced to introduced semantic vagueness into his system of counterfactuals. In this paper it is argued that there is a simpler and purely epistemic explanation of these cases that avoids the need for introducing semantic vagueness into the (...) semantics for counterfactuals. (shrink)

I give reasons stemming from the nature of narrative thinking why two-antecedent conditionals, most naturally expressed as "Suppose A. Suppose moreover B. Then C" the two antecedents play different roles. I formalise this idea with a two-dimensional similarity relation between possible worlds.

'It is widely agreed that contraposition, strengthening the antecedent and hypothetical syllogism fail for subjunctive conditionals', write Brogaard and Salerno in (2008: Counterfactuals and context, Analysis 68.1, 39–46). In that article they argue that the putative counterexamples to these principles are actually no threat, on the grounds that they involve a certain kind of illicit contextual shift. -/- Here I argue that this particular kind of contextual shift, if it is properly so called, is not generally illicit, and that therefore (...) the counterexamples shouldn't be blocked with the kind of blanket restriction Brogaard and Salerno advocate. The idea that the reasoning patterns in question can be vindicated given restrictions still seems promising; the purpose of this note is to show that the simple restriction proposed by Brogaard and Salerno isn't the right way of going. (shrink)

Statements about the future are central in everyday conversation and reasoning. How should we understand their meaning? The received view among philosophers treats will as a tense: in ‘Cynthia will pass her exam’, will shifts the reference time forward. Linguists, however, have produced substantial evidence for the view that will is a modal, on a par with must and would. The different accounts are designed to satisfy different theoretical constraints, apparently pulling in opposite directions. We show that these constraints are (...) jointly satisfied by a novel modal account of will. On this account, will is a modal but doesn't work as a quantifier over worlds. Rather, the meaning of will involves a selection function similar to the one used by Stalnaker in his semantics for conditionals. The resulting theory yields a plausible semantics and logic for will and vindicates our intuitive views about the attitudes that rational agents should have towards future-directed contents. (shrink)

When people want to identify the causes of an event, assign credit or blame, or learn from their mistakes, they often reflect on how things could have gone differently. In this kind of reasoning, one considers a counterfactual world in which some events are different from their real-world counterparts and considers what else would have changed. Researchers have recently proposed several probabilistic models that aim to capture how people do (or should) reason about counterfactuals. We present a new model and (...) show that it accounts better for human inferences than several alternative models. Our model builds on the work of Pearl (2000), and extends his approach in a way that accommodates backtracking inferences and that acknowledges the difference between counterfactual interventions and counterfactual observations. We present six new experiments and analyze data from four experiments carried out by Rips (2010), and the results suggest that the new model provides an accurate account of both mean human judgments and the judgments of individuals. (shrink)

I argue that Lewis's counterfactual theory of causation, given his treatment of counterfactuals in terms of world-comparative similarity faces insuperable problems in the form of the problem of effects and the problem of epiphenomena.

In this paper I argue that there is a difficulty for Fine's exact semantics for counterfactuals. The difficulty undermines Fine's reasons for preferring exact semantics to possible worlds semantics.

(No abstract is available for this citation).

I reply to Ahmed’s rejection (2011) of my argument (Walters 2009) that all counterfactuals with true antecedents and consequents are themselves true.

Is A & C sufficient for the truth of ‘if A were the case, C would be the case’? Jonathan Bennett thinks not, although the counterexample he gives is inconsistent with his own account of counterfactuals. In any case, I argue that anyone who accepts the case of Morgenbesser's coin, as Bennett does, should reject Bennett’s counterexample. Moreover, I show that the principle underlying his counterexample is unmotivated and indeed false. More generally, I argue that Morgenbesser’s coin commits us to (...) the sufficiency of A & C for the truth of the corresponding counterfactual. (shrink)

This paper concerns a thorny problem posed by conditional requirements: we expect some modal conditionals of the form ‘if p, then it must be that p’ to be false, yet they all come out true given two basic assumptions needed to account for ordinary conditional requirement like ‘If the light turns red, then cars must stop’. The first assumption is a semantic expectation linking conditional requirements with absolute ones, the second is the possible-worlds-based definition of modal sentences. Keeping the former (...) means giving up the latter, a result with profound implications for Kratzer’s formal semantics, modifications thereof, as well as deontic logics. (shrink)

The traditional Lewis–Stalnaker semantics treats all counterfactuals with an impossible antecedent as trivially or vacuously true. Many have regarded this as a serious defect of the semantics. For intuitively, it seems, counterfactuals with impossible antecedents—counterpossibles—can be non-trivially true and non-trivially false. Whereas the counterpossible "If Hobbes had squared the circle, then the mathematical community at the time would have been surprised" seems true, "If Hobbes had squared the circle, then sick children in the mountains of Afghanistan at the time would (...) have been thrilled" seems false. Many have proposed to extend the Lewis–Stalnaker semantics with impossible worlds to make room for a non-trivial or non-vacuous treatment of counterpossibles. Roughly, on the extended Lewis–Stalnaker semantics, we evaluate a counterfactual of the form "If A had been true, then C would have been true" by going to closest world—whether possible or impossible—in which A is true and check whether C is also true in that world. If the answer is "yes", the counterfactual is true; otherwise it is false. Since there are impossible worlds in which the mathematically impossible happens, there are impossible worlds in which Hobbes manages to square the circle. And intuitively, in the closest such impossible worlds, sick children in the mountains of Afghanistan are not thrilled—they remain sick and unmoved by the mathematical developments in Europe. If so, the counterpossible "If Hobbes had squared the circle, then sick children in the mountains of Afghanistan at the time would have been thrilled" comes out false, as desired. In this paper, I will critically investigate the extended Lewis–Stalnaker semantics for counterpossibles. I will argue that the standard version of the extended semantics, in which impossible worlds correspond to maximal, logically inconsistent entities, fails to give the correct semantic verdicts for many counterpossibles. In light of the negative arguments, I will then outline a new version of the extended Lewis–Stalnaker semantics that can avoid these problems. (shrink)

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.