In this paper, we develop a novel response to counterfactual scepticism, the thesis that most ordinary counterfactual claims are false. In the process we aim to shed light on the relationship between debates in the philosophy of science and debates concerning the semantics and pragmatics of counterfactuals. We argue that science is concerned with many domains of inquiry, each with its own characteristic entities and regularities; moreover, statements of scientific law often include an implicit ceteris paribus clause (...) that restricts the scope of the associated regularity to circumstances that are ‘fitting’ to the domain in question. This observation reveals a way of responding to scepticism while, at the same time, doing justice both to the role of counterfactuals in science and to the complexities inherent in ordinary counterfactual discourse and reasoning. (shrink)

I have argued for a kind of ‘counterfactual scepticism’: most counterfactuals ever uttered or thought in human history are false. I briefly rehearse my main arguments. Yet common sense recoils. Ordinary speakers judge most counterfactuals that they utter and think to be true. A common defence of such judgments regards counterfactuals as context-dependent: the proposition expressed by a given counterfactual can vary according to the context in which it is uttered. In normal contexts, the counterfactuals that we (...) utter are typically true, the defence insists, while granting that there may be more rarefied contexts in which they are false. I give a taxonomy of such contextualist replies. One could be a contextualist about the counterfactual connective, about its antecedent, or about its consequent. I offer some general concerns about all these varieties of contextualism. I then focus especially on antecedent-contextualism, as I call it. I firstly raise some high-level objections to it. Then, I look at such a contextualist account due to Sandgren and Steele. I think it has many virtues, but also some problems. I conclude with some avenues for future research. (shrink)

The following semantics for counterfactuals is fairly standard: for a counterfactual to be true, the closest antecedent worlds have to be consequent worlds. Closeness is measured by overall similarity of worlds to an evaluation world. There is a range of interrelated challenges to this account: counterfactual scepticism, ‘Hegel’-, ‘Sobel’-, and ‘Heim’-sequences. So far there is no unified solution to these challenges. I discuss a solution that preserves the standard semantics by writing the shifty parameter into pragmatics. The (...) solution has been suggested by Križ for Sobel- and Heim-sequences, yet I argue that it can be generalized to counterfactual scepticism. Conditionals are subject to a pattern which is familiar from descriptions. Everyday counterfactuals are semantically homogeneous and pragmatically non-maximal. Homogeneity: a counterfactual is neither true nor false if only some but not all closest antecedent worlds are consequent worlds. Non-maximality: in many contexts, not all but only practically all closest antecedent worlds have to be consequent worlds for the utterance of a counterfactual to say something true if the difference does not matter for the purposes of conversation. (shrink)

If one flips an unbiased coin a million times, there are 2 1,000,000 series of possible heads/tails sequences, any one of which might be the sequence that obtains, and each of which is equally likely to obtain. So it seems (1) 'If I had tossed a fair coin one million times, it might have landed heads every time' is true. But as several authors have pointed out, (2) 'If I had tossed a fair coin a million times, it wouldn't have (...) come up heads every time' will be counted as true in everyday contexts. And according to David Lewis' influential semantics for counterfactuals, (1) and (2) are contradictories. We have a puzzle. We must either (A) deny that (2) is true, (B) deny that (1) is true, or (C) deny that (1) and (2) are contradictories, thus rejecting Lewis' semantics. In this paper I discuss and criticize the proposals of David Lewis and more recently J. Robert G. Williams which solve the puzzle by taking option (B). I argue that we should opt for either (A) or (C). (shrink)

Williamson has argued against scepticism concerning our metaphysically modal knowledge, by arguing that standard patterns of suppositional reasoning to counterfactual conclusions provide reliable sources of correct ascriptions of possibility and necessity. The paper argues that, while Williamson’s claims relating to necessity may well be right, he has not provided adequate reasons for thinking that the familiar modes of counterfactual reasoning to which he points generalise to provide a decent route to ascriptions of possibility. The paper also explores (...) another path to ascriptions of possibility that may be extracted from Williamson’s ideas, before briefly considering the general status of counterfactual reasoning in relation to our knowledge of possibilities. (shrink)

The Principle of Credulity: 'It is basic to human knowledge of the world that we believe things are as they seem to be in the absence of positive evidence to the contrary' [Swinburne 1996: 133]. This underlies the Evidential Problem of Evil, which goes roughly like this: ‘There appears to be a lot of suffering, both animal and human, that does not result in an equal or greater utility. So there's probably some pointless suffering. As God's existence precludes pointless suffering, (...) theism is implausible.’ CORNEA is the principle that observation O raises hypothesis H's probability only if O is more probable given H than it is given not-H. Theists sometimes maintain that apparently pointless suffering is just as likely given theism as atheism (I support this claim by appealing to a Lewisian account of the relevant counterfactuals). Given CORNEA, therefore, what we see of suffering does not make theism unlikely. I maintain that a consequence of so deploying CORNEA is that CORNEA and the Principle of Credulity are incompatible. We are left with a skeptical paradox. CORNEA is a consequence of Bayes’s Theorem, I argue; but it is incompatible with a presupposition of empirical science, namely, that appearances create epistemic warrant, ceteris paribus. External-world probability skepticism follows. I treat the paradox as real. First, I offer an account of how we strike a balance in practice between CORNEA, on the one hand, and the Principle of Credulity and the scientific enterprise on the other. Second, I try to resolve the paradox outright by rejecting the Principle of Credulity and maintaining that the scientific project remains well motivated even allowing probability skepticism. On either response to the paradox, the Evidential Problem of Evil continues to have serious, but defeasible, force against theism. (shrink)

Metaphysical modalities are definable from counterfactual conditionals, and the epistemology of the former is a special case of the epistemology of the latter. In particular, the role of conceivability and inconceivability in assessing claims of possibility and impossibility can be explained as a special case of the pervasive role of the imagination in assessing counterfactual conditionals, an account of which is sketched. Thus scepticism about metaphysical modality entails a more far-reaching scepticism about counterfactuals. The account is (...) used to question the significance of the distinction between a priori and a posteriori knowledge. (shrink)

Counterfactual scepticism holds that most ordinary counterfactuals are false. The main argument for this view appeals to a ‘chance undermines would’ principle: if ψ would have some chance of not obtaining had ϕ obtained, then ϕ □→ ψ is false. This principle seems to follow from two fairly weak principles, namely, that ‘chance ensures could’ and that ϕ □→ ψ and ϕ ⋄→ ¬ ψ clash. Despite their initial plausibility, I show that these principles are independently problematic: given (...) some modest closure principles, they entail absurdities. Moreover, on the most promising strategy for saving these principles, they do not, in the relevant sense, entail the chance-undermines-would principle. Instead, they entail a principle that only supports counterfactual indeterminism, the view that most ordinary counterfactuals are chancy, that is, not settled true. I demonstrate this by developing an indeterminist semantics that vindicates the clash and chance-ensures-could principles but not the chance-undermines-would principle. This view, I argue, offers a better account of our credal and linguistic judgements than counterfactual scepticism. (shrink)

Tyler Burge says that first-person authority can be reconciled with anti-individualism about the intentional by denying part of the "Cartesian conception" of authority, which claims that I am actually authoritative about my intentional attitudes in counterfactual situations. This clause, he says, wrongly conflates the evaluation-conditions for sceptical doubts about the "external" world with the conditions for classifying intentional attitudes in counterfactual situations. This paper argues that the kind of possibility needed to understand external-world scepticism justifies the conflation (...) and that Burge can reject the Cartesian conception only if he rejects either metaphysical realism or anti-individualism. (shrink)

This paper outlines a non-reductive counterfactual account of grounding along interventionist lines, and uses the account to argue that taking grounding seriously requires ascribing non-trivial truth-conditions to a range of counterpossible counterfactuals. This result allows for a diagnosis of a route to scepticism about grounding, as deriving at least in part from scepticism about non-trivial counterpossible truth and falsity.

Available from UMI in association with The British Library. Requires signed TDF. ;The main part of the thesis concerns how things, in the sense of individuals, might have been. The topic is what limits there are on the counterfactual possibilities for individuals: in other words, what essential properties, if any, they have. ;In Chapters 3-6 three answers to this question that have been given in recent philosophical literature are examined. They are: that each thing has a unique individual essence (...) ; that there are features of the origin of an individual without which it could not possibly have existed ; and, finally, that there are sortal concepts that represent essential properties of the things that fall under them . ;All of these answers, and many of the arguments that have been given for them, are criticised. Sometimes the criticism takes the form of pointing to unpalatable consequences that result from the acceptance of the doctrine in question. Sometimes the criticism consists in pointing to difficulties or inadequacies in the arguments that have been presented in its favour. ;A preliminary chapter prepares the ground by setting out the conceptual framework, and the chief formal characteristics, of the essentialism discussed in the later chapters. Chapter 2 discusses the nature of necessary a posteriori truth, touching on questions in the philosophy of language and mind concerning the notion of de re thought. ;It is argued that essentialism about natural kinds raises problems of its own: some of these are discussed in Chapters 7 and 8. Here the main topic is the connection between semantic theory and natural kind essentialism. Concluding that the essentialism should be regarded as in an important sense independent of semantic theory, the chapters add to, and also criticise, the work of other writers who have reached the same verdict. Scepticism is also expressed about the independent plausibility of natural kind essentialism. ;Recent interest in essentialism owes its genesis chiefly to the work of Saul Kripke and Hilary Putnam: these figures stand in the background throughout the discussion. Among the other writers whose work is discussed are Baruch Brody, Gareth Evans, Graeme Forbes, Colin McGinn, J. L. Mackie, D. H. Mellor, Nathan Salmon, and David Wiggins. (shrink)

I argue that a pragmatic scepticism about metaphysical modality is a perfectly reasonable position to maintain. I then illustrate the difficulties and limitations associated with some strategies for defeating such scepticism. These strategies appeal to associations between metaphysical modality and the following: objective probability, counterfactuals and distinctive explanatory value.

Dispositions can combine as vector sums. Recent authors on dispositions, such as George Molnar and Stephen Mumford, have responded to this feature of dispositions by introducing a distinction between effects and contributions to effects, and by identifying disposition-manifestations with the latter. But some have been sceptical of the reality or knowability of component vectors; Jennifer McKitrick (forthcoming) presses these concerns against the conception of manifestations as contributions to effects. In this paper, I aim to respond to McKitrick's arguments and to (...) defend the metaphysical and epistemological propriety of component vectors. My strategy appeals to varying kinematic frames of reference. By transforming to the appropriate non-inertial frame, component acceleration vectors can be transformed into resultant acceleration vectors, and in such frames they become directly observable. Being a component acceleration vector and being a resultant acceleration vector are both frame-dependent properties of properties; they are not to be thought of as intrinsic or fundamental properties of an acceleration vector, but as artefacts of our frame-dependent notation for representing vector quantities. To conclude the paper, I defend the view proposed against two styles of objection. The first objection resurrects scepticism about component vectors as scepticism about fundamental component vectors. The second objection questions the need for reference frames in the explanation by invoking a 'counterfactual' theory of contributions. (shrink)

There exists a widespread consensus amongst contemporary jurisprudents, positivists and non-positivists alike, that the meaning of ‘obligation’ should not radically shift from law to morality, or any of the other domains of practical reason. Yet there is limited effort in contemporary discussions of legal obligation to engage with the metaphysics of normativity with an eye to a well-founded account of those elements that deliver its non-conditional character. On a recent occasion I discussed the shortcomings of a prominent positivist account of (...) legal obligation, that of Jules Coleman. In this chapter I turn to a prominent non-positivist account, the model of principle, and argue that, even though it identifies key elements or conditions of normativity simpliciter, it stops short of delivering a conclusive account of unconditional legal obligation, an account that would place legal obligation in the same continuum with all other types of obligation. Taking up from where the model of principle halts, I propose a complementary—if more fundamental—account of normativity simpliciter, which I dub the model of norms. I make a case for it, by looking into universal conditions of normativity and, in conclusion, offer some more specific remarks about the advantages of the model of norms over other competing models. Part 2 looks into the account of legal obligation tendered by the model of principle. According to it, law is an instance of action-directing action or action that purports to get other agents to comply with the ends it sets out to attain. The idea here is that the very logic of action-direction draws moral reasons—principles—into the picture of legal obligation, as the one item that can explain how and whether the facts of a social practice, which purports to direct action, come to acquire the status of reasons for action for the subjects of law. Subsequently, this model is contrasted with an alternative model of obligation that takes facts of authority to constitute reasons of action in virtue solely of their structure. In conclusion it is argued that, in contrast to the second model, the model of principle manages to capture what is distinctive about action-directing action in the domain of law—that is, the special normative significance of the possibility to coerce others under a scheme of public institutions. Part 3 opens by pointing to a more widespread worry that needs to be addressed before the model of principle can be deemed fit for the role it is employed—the worry relates to the ability of principles to constitute genuine reasons for action. In particular, the enquiry investigates the nature of principles and their ability to avoid certain flaws that might pertain to reasons for action in general. In taking up this line of enquiry the paper looks into the more general debate on normativity with a view to specifying requirements that anything which purports to be a reason ought to meet. I employ a rationalist analysis of normativity, which brings the idea that intentional thought is normative to bear on the analysis of the meaning of normative terms, such as ‘ought’, ‘obligation’, ‘duty’. In conclusion, I argue that the content of normativity consists in normative facts—ie norms—which purport to model the content of ideal—or counterfactual—states of the will. Such norms give exhaustively the content of normativity. In light of the above, part 4 advances a two-layered model of norms, with the higher level being populated by norms simpliciter, and the lower by norms in a domain. When considered jointly the two layers ground the possibility of non-conditional obligation without evoking moral realism and the concomitant suspicion of scepticism. On the face of it some key advantages of the model of norms are discussed over the two other models of legal obligation, that of principle and that of authority. On the one hand norms resist the ‘talking past each other objection’ which is commonly levelled against principles. On the other, norms are much better suited to account for the moral limits of action-directing action than either principles or facts of authority, for they illustrate cogently that the grounds of any reason for action already include a concern for others’ autonomy. (shrink)

Philosophers such as Robert Nozick have argued that knowledge must be sensitive, in roughly the sense that if what one knew had been false, one would not have believed it. Such a counterfactual constraint has been used to explain the appeal of scepticism. This chapter argues that no version of the constraint is correct. It also criticizes the variant of Nozick's approach developed by Keith DeRose on which the standard for the application of the word ‘know’ depends on (...) the conversational context. A version of the argument given by Hilary Putnam that if one was a brain in a vat, one could not think that one was constructed using perceptual demonstrative expressions. (shrink)

Dretske's conclusive reasons account of knowledge is designed to explain how epistemic closure can fail when the evidence for a belief does not transmit to some of that belief's logical consequences. Critics of Dretske dispute the argument against closure while joining Dretske in writing off transmission. This paper shows that, in the most widely accepted system for counterfactual logic , conclusive reasons are governed by an informative, non-trivial, logical transmission principle. If r is a conclusive reason for believing p (...) in Dretske's sense, and if p logically implies q, and if p and q satisfy one additional condition, it follows that r is a conclusive reason for believing q. After introducing this additional condition, I explain its intuitive import and use the condition to shed new light on Dretske's response to scepticism, as well as on his distinction between the so-called ‘lightweight’ and ‘heavyweight’ implications of a piece of perceptual knowledge. (shrink)

After providing some historical and systematic background, I introduce the structure of a very natural and influential sceptical underdetermination argument. The argument assumes that it is metaphysically possible for a deceived subject to have the same evidence that a non-deceived subject has, and tries to draw consequences about justification from that assumption of metaphysical possibility. I first variously object to the transition from the assumption to its supposed consequences. In the central part of the paper, I then critically consider some (...) influential ways of bridging the gap between the assumption and its supposed consequences, which generally consist in strengthening the assumption from one of metaphysical possibility into one of either counterfactual implication or entailment. The discussion indicates that epistemic facts are much more independent from metaphysically modal facts than the sceptical underdetermination argument requires. (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)

This paper discusses a puzzle raised by Sharon Berry, published in Analysis. The question in the background of this puzzle is how we should deal with seemingly plausible possibility judgements that commit us to counterfactual truths that find no basis in reality. Three answers to this question and their corresponding solutions to the puzzle will be discussed. The last answer provides a way to make sense of the claim that it is in some cases indeterminate whether a proposition is (...) possible and offers an account of indeterminate modal status. (shrink)

Counterfactuals is David Lewis' forceful presentation of and sustained argument for a particular view about propositions which express contrary to fact conditionals, including his famous defense of realism about possible worlds and his theory of laws of nature.

Counterfactual attitudes like imagining, dreaming, and wishing create a problem for the standard formal semantic theory of de re attitude ascriptions. I show how the problem can be avoided if we represent an agent's attitudinal possibilities using "multi-centered worlds", possible worlds with multiple distinguished individuals, each of which represents an individual with whom the agent is acquainted. I then present a compositional semantics for de re ascriptions according to which singular terms are "assignment-sensitive" expressions and attitude verbs are "assignment (...) shifters". (shrink)

Among the many philosophers who hold that causal facts1 are to be explained in terms of—or more ambitiously, shown to reduce to—facts about what happens, together with facts about the fundamental laws that govern what happens, the clear favorite is an approach that sees counterfactual dependence as the key to such explanation or reduction. The paradigm examples of causation, so advocates of this approach tell us, are examples in which events c and e— the cause and its effect— both (...) occur, but: had c not occurred, e would not have occurred either. From this starting point ideas proliferate in a vast profusion. But the remarkable disparity among these ideas should not obscure their common foundation. Neither should the diversity of opinion about the prospects for a philosophical analysis of causation obscure their importance. For even those philosophers who see these prospects as dim—perhaps because they suffer post-Quinean queasiness at the thought of any analysis of any concept of interest—can often be heard to say such things as that causal relations among events are somehow “a matter of” the patterns of counterfactual dependence to be found in them. (shrink)

I argue that most counterfactuals are false.

The desirability of what actually occurs is often influenced by what could have been. Preferences based on such value dependencies between actual and counterfactual outcomes generate a class of problems for orthodox decision theory, the best-known perhaps being the so-called Allais Paradox. In this paper we solve these problems by extending Richard Jeffrey's decision theory to counterfactual prospects, using a multidimensional possible-world semantics for conditionals, and showing that preferences that are sensitive to counterfactual considerations can still be (...) desirability maximising. We end the paper by investigating the conditions necessary and sufficient for a desirability function to be an expected utility. It turns out that the additional conditions imply highly implausible epistemic principles. (shrink)

This paper investigates propositional hyperintensionality in counterfactuals. It starts with a scenario describing two children playing on a seesaw and studies the truth-value predictions for counterfactuals by four different semantic theories. The theories in question are Kit Fine’s truthmaker semantics, Luis Alonso-Ovalle’s alternative semantics, inquisitive semantics and Paolo Santorio’s syntactic truthmaker semantics. These predictions suggest that the theories that distinguish more of a given set of intensionally equivalent sentences (Fine and Alonso-Ovalle’s) fare better than those that do not (inquisitive semantics (...) and Santorio’s). Then we investigate how inquisitive semantics and Santorio can respond to these results. They can respond to them by helping themselves to considerations from Hurford disjunctions, disjunctions whose disjuncts stand in an entailment relation to one another. I argue that considerations from Hurford disjunctions are ad hoc modifications merely to predict the expected results. I conclude that the scenarios suggest a need for more fine-grained theories of sentential meaning in general. (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)

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.

Aristotle is essentially human; that is, for all possible worlds metaphysically consistent with our own, if Aristotle exists, then he is human. This is a claim about the essential property of an object. The claim that objects have essential properties has been hotly disputed, but for present purposes, we can bracket that issue. In this essay, we are interested, rather, in the question of whether properties themselves have essential properties (or features) for their existence. We call those who suppose they (...) do “property essentialists”; those who do not, “property anti-essentialists,” or “quidditists.” We offer two complementary arguments. Our total argument is under-girded by two assumptions: transworld identity theory and “received view” counterfactual semantics, a la David Lewis. We then argue that, if one presumes that these are true, then one risks running headlong into paradox if one also accepts property anti-essentialism. That's the first argument. By contrast, if one accepts these same assumptions in conjunction with property essentialism, then the paradox is avoided. This is the second argument. We take it that our arguments work to show that, between property essentialism and quidditism, the property essentialist is on better footing. Plausibly, properties themselves do have essential properties for their existence. (shrink)

This essay calls attention to a set of linguistic interactions between counterfactual conditionals, on one hand, and possibility modals like could have and might have, on the other. These data present a challenge to the popular variably strict semantics for counterfactual conditionals. Instead, they support a version of the strict conditional semantics in which counterfactuals and possibility modals share a unified quantificational domain. I’ll argue that pragmatic explanations of this evidence are not available to the variable analysis. And (...) putative counterexamples to the unified strict analysis, on careful inspection, in fact support it. Ultimately, the semantics of conditionals and modals must be linked together more closely than has sometimes been recognized, and a unified strict semantics for conditionals and modals is the only way to fully achieve this. (shrink)

I argue that the suppositional view of conditionals, which is quite popular for indicative conditionals, extends also to subjunctive or counterfactual conditionals. According to this view, conditional judgements should not be construed as factual, categorical judgements, but as judgements about the consequent under the supposition of the antecedent. The strongest evidence for the view comes from focusing on the fact that conditional judgements are often uncertain; and conditional uncertainty, which is a well-understood notion, does not function like uncertainty about (...) matters of fact. I argue that the evidence for this view is as strong for subjunctives as it is for indicatives. (shrink)

This paper considers how counterfactuals should be evaluated on the assumption that determinism is true. I argue against Lewis's influential view that the actual laws of nature would have been false if something had happened that never actually happened, and in favour of the competing view that history would have been different all the way back. I argue that we can do adequate justice to our ordinary practice of relying on a wide range of historical truths in evaluating counterfactuals by (...) saying that, in typical cases, history would have been only *very slightly* different until shortly before the relevant time. The paper also draws some connections between the puzzle about counterfactuals under determinism and the debate about whether determinism entails that no-one can ever do otherwise than they in fact do. (shrink)

Counterfactuals are typically thought--given the force of Sobel sequences--to be variably strict conditionals. I go the other way. Sobel sequences and (what I call) Hegel sequences push us to a strict conditional analysis of counterfactuals: counterfactuals amount to some necessity modal scoped over a plain material conditional, just which modal being a function of context. To make this worth saying I need to say just how counterfactuals and context interact. No easy feat, but I have something to say on the (...) matter. (shrink)

Rational agents face choices, even when taking seriously the possibility of determinism. Rational agents also follow the advice of Causal Decision Theory (CDT). Although many take these claims to be well-motivated, there is growing pressure to reject one of them, as CDT seems to go badly wrong in some deterministic cases. We argue that deterministic cases do not undermine a counterfactual model of rational deliberation, which is characteristic of CDT. Rather, they force us to distinguish between counterfactuals that are (...) relevant and ones that are irrelevant for the purposes of deliberation. We incorporate this distinction into decision theory to develop ‘Selective Causal Decision Theory’, which delivers the correct recommendations in deterministic cases while respecting the key motivations behind CDT. (shrink)

Common sense suggests that counterfactuals are capable of truth and falsity, and that their truth values depend on more than just the actual course of events. Projectivists, like Mackie, deny the first; reductivists, like Lewis, deny the second. I criticize Mackie's and Lewis's theories, thereby defending realism. There are parallel issues and positions concerning the other concepts of the natural necessity family. A realist theory may also have a positive part, consisting of an account of some of the conceptual relations (...) within this family. I try to cast light on the counterfactual by postulating a relation of accessibility between possible worlds - accessibility at the 'point' at which an event occurs. (shrink)

If the laws are deterministic, then standard theories of counterfactuals are forced to reject at least one of the following conditionals: 1) had you chosen differently, there would not have been a violation of the laws of nature; and 2) had you chosen differently, the initial conditions of the universe would not have been different. On the relevant readings—where we hold fixed factors causally independent of your choice—both of these conditionals appear true. And rejecting either one leads to trouble for (...) philosophical theories which rely upon counterfactual conditionals—like, for instance, causal decision theory. Here, I outline a semantics for counterfactual conditionals which allows us to accept both (1) and (2). And I discuss how this semantics deals with objections to causal decision theory from Arif Ahmed. (shrink)

There is, no doubt, a temptation to treat preventions, such as ‘the father’s grabbing the child prevented the accident’, and cases of ‘causation’ by omission, such as ‘the father’s inattention was the cause of the child’s accident’, as cases of genuine causation. I think they are not, and in this paper I defend a theory of what they are. More specifically, the counterfactual theory defended here is that a claim about prevention or ‘causation’ by omission should be understood not (...) as being directly about actual genuine causation but primarily as a counterfactual claim about genuine causation.1 The relation between actual causation and the mere possibility of causation allows my theory to explain both the difference and the similarity between the two notions (causation and prevention/omission). Further, the difference explains certain intuitions we have and the similarity justifies and explains the fact that for practical purposes we usually treat preventions and omissions as if they were genuine causation. Finally, the fact that this counterfactual theory of prevention and omission takes causation as primitive suggests that it is consistent with any theory of causation. This allows us to construct two arguments against what I will call genuinism, the view that cases of prevention and ‘causation’ by omission really are cases of genuine causation. In section II I show that genuinism does not account for the so-called intuition of difference. In section III I outline a number of problems that various theories of causation have with preventions and ‘causation’ by omission. These problems are ipso facto problems for genuinism, whereas I show in section V how the counterfactual theory solves those problems. Further, I answer a genuinist argument based on another type of intuition—the genuinist intuition—by showing why we have that intuition and how it should be handled (section VI). (shrink)

This paper is concerned with counterfactual logic and its implications for the modal status of mathematical claims. It is most directly a response to an ambitious program by Yli-Vakkuri and Hawthorne (2018), who seek to establish that mathematics is committed to its own necessity. I claim that their argument fails to establish this result for two reasons. First, their assumptions force our hand on a controversial debate within counterfactual logic. In particular, they license counterfactual strengthening— the inference (...) from ‘If A were true then C would be true’ to ‘If A and B were true then C would be true’—which many reject. Second, the system they develop is provably equivalent to appending Deduction Theorem to a T modal logic. It is unsurprising that the combination of Deduction Theorem with T results in necessitation; indeed, it is precisely for this reason that many logicians reject Deduction Theorem in modal contexts. If Deduction Theorem is unacceptable for modal logic, it cannot be assumed to derive the necessity of mathematics. (shrink)

A number of recent authors (Galles and Pearl, Found Sci 3 (1):151–182, 1998; Hiddleston, Noûs 39 (4):232–257, 2005; Halpern, J Artif Intell Res 12:317–337, 2000) advocate a causal modeling semantics for counterfactuals. But the precise logical significance of the causal modeling semantics remains murky. Particularly important, yet particularly under-explored, is its relationship to the similarity-based semantics for counterfactuals developed by Lewis (Counterfactuals. Harvard University Press, 1973b). The causal modeling semantics is both an account of the truth conditions of counterfactuals, and (...) an account of which inferences involving counterfactuals are valid. As an account of truth conditions, it is incomplete. While Lewis's similarity semantics lets us evaluate counterfactuals with arbitrarily complex antecedents and consequents, the causal modeling semantics makes it hard to ascertain the truth conditions of all but a highly restricted class of counterfactuals. I explain how to extend the causal modeling language to encompass a wider range of sentences, and provide a sound and complete axiomatization for the extended language. Extending the truth conditions for counterfactuals has serious consequences concerning valid inference. The extended language is unlike any logic of Lewis's: modus ponens is invalid, and classical logical equivalents cannot be freely substituted in the antecedents of conditionals. (shrink)

Stalnaker's Thesis about indicative conditionals is, roughly, that the probability one ought to assign to an indicative conditional equals the probability that one ought to assign to its consequent conditional on its antecedent. The thesis seems right. If you draw a card from a standard 52-card deck, how confident are you that the card is a diamond if it's a red card? To answer this, you calculate the proportion of red cards that are diamonds -- that is, you calculate the (...) probability of drawing a diamond conditional on drawing a red card. Skyrms' Thesis about counterfactual conditionals is, roughly, that the probability that one ought to assign to a counterfactual equals one's rational expectation of the chance, at a relevant past time, of its consequent conditional on its antecedent. This thesis also seems right. If you decide not to enter a 100-ticket lottery, how confident are you that you would have won had you bought a ticket? To answer this, you calculate the prior chance--that is, the chance just before your decision not to buy a ticket---of winning conditional on entering the lottery. The central project of this article is to develop a new uniform theory of conditionals that allows us to derive a version of Skyrms' Thesis from a version of Stalnaker's Thesis, together with a chance-deference norm relating rational credence to beliefs about objective chance. (shrink)

Moritz Schulz explores counterfactual thought and language: what would have happened if things had gone a different way. Counterfactual questions may concern large scale derivations or small scale evaluations of minor derivations. A common impression, which receives a thorough defence in the book, is that oftentimes we find it impossible to know what would have happened. However, this does not mean that we are completely at a loss: we are typically capable of evaluating counterfactual questions probabilistically: we (...) can say what would have been likely or unlikely to happen. Schulz describes these probabilistic ways of evaluating counterfactual questions and turns the data into a novel account of the workings of counterfactual thought. (shrink)