A brief account of David K. Lewis's argument for possible worlds in Counterfactuals and his elaboration of it in On the Plurality of Worlds.

This entry provides a brief exposition and formal reconstruction of the argument for possible worlds in David Lewis's _Counterfactuals_.

David Lewis has shocked the philosophical community with his original version of extreme modal realism according to which “every way that a world could possibly be is a way that some world is”. Logical Space is a plenitude of isolated physical worlds, each being the actualization of some way in which a world could be, that bear neither spatiotemporal nor causal relations to each other. Lewis has given independent, converging arguments for this. One is the argument from the (...) indexicality of actuality, the other an elaborate cost-benefit argument of the inference-to-the-best explanation sort to the effect that a systematic analysis of a number of concepts, including modality, causality, propositions and properties, fares better under his theory than under any rival one that takes a possible world to be either a linguistic entity or an ersatz abstract entity such as a maximal compossible set of properties, propositions or states of affairs. Lewis' legion of critics have confined themselves mostly to attempts at a reductio ad absurdum of his theory or to objections to his various analyses. The indexical argument, on the other hand, has not been subject to careful critical scrutiny. It is the purpose of this paper to show that this argument cannot withstand such scrutiny. Its demise, however, leaves untouched his argument from the explanatory superiority for his extreme modal realism. (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.

Conditional structures lie at the heart of the sciences, humanities, and everyday reasoning. It is hence not surprising that conditional logics – logics specifically designed to account for natural language conditionals – are an active and interdisciplinary area. The present book gives a formal and a philosophical account of indicative and counterfactual conditionals in terms of Chellas-Segerberg semantics. For that purpose a range of topics are discussed such as Bennett’s arguments against truth value based semantics for indicative conditionals.

In lieu of an abstract, here is a brief excerpt of the content:PARODY AND THE ARGUMENT FROM PROBABILITY IN THE APOLOGY by Thomas J. Lewis Over a century ago James Riddell pointed out that Socrates' defense speech in die Apology closely followed the standard form of Athenian forensic rhetoric. He called the Apology "artistic to the core," and he identified parts of "the subde rhetoric of this defense."1 Since then many scholars have explicated the rhetorical elements in Socrates' defense.2 (...) Their work has led in turn to recent attempts to integrate the rhetorical form into an overall understanding of the meaning and significance of the Apology? The puzzle to be solved is what to make of the fact that Socrates disclaims the ability and the intention to use rhetoric in a speech which is itself a rhetorical masterpiece. R. E. Allen raises the possibility thatby using the techniques ofrhetoric and at the same time denying that he is using them Socrates is dissembling or lying. However, Allen rejects this possibility and interprets Socrates' falsehood as only a surface or apparent falsehood. According to Allen it is ironic parody of a disreputable rhetoric which seeks to convince without concern for the truth.4 For Allen the object of the parody is base rhetoric in general, the type of rhetoric denounced by Socrates in the Gorgias as "rhetoric aiming at gratification and pleasure, and indifferent to truth and the good of the soul."5 Two subsequent articles, one by Kenneth Seeskin, the other by Douglas Feaver andJohn Hare, support the view that Socrates is parodying the debased form of rhetoric. However, they place somewhat different emphasis on the exact object of the parody. They argue that the object of Socrates' rhetorical parody is Gorgias' Pahmedes, rather than pandering rhetoric in general.6 After summarizing the many rhetorical similarities between Gorgias' Palamedes and Socrates' defense speech, Seeskin concludes that "Gorgias' Philosophy and Literature, © 1990, 14: 359-366 360Philosophy and Literature Palamedes is not a masterpiece of world literature; it is a collection of topoi—tried and true devices for winning acquittal... [whereas] despite his disclaimer, Socrates' speech is no amateur performance. On the contrary, he knew all the tricks of the trade and employed them with consummate skill" (p. 97). Seeskin uses Plato's Gorgias to explain how Socrates' rhetoric fits within an overall understanding of the Apology. He notes the two types ofrhetoric presented in the Gorgias: base rhetoric, a species of flattery which aims at gratification; and philosophic or true rhetoric which aims at improving the soul. Then Seeskin makes a crucial point. He insists it is not enough to distinguish between base rhetoric and philosophic rhetoric; there must be a way to identify a given instance of rhetoric as either base rhetoric or as philosophic rhetoric. Moreover, he cautions that distinguishing the one from the other is no easy task. "It is impossible to tell them apart on the basis of technique alone. Base rhetoric is no less polished for its baseness.... Nor can one tell them apart on the basis of their stated goals. Flattery succeeds only to the extent that it can pass itself off as something better" (p. 98). Thus, if Socrates and Palamedes employ the same rhetorical devices, Seeskin wonders how we can tell which type ofrhetoric is in the Apology. "Somewhere in the Apology of Socrates there ought to be a clue which allows one to distinguish his defense from the 'standard' defense composed by Gorgias" (p. 99). Seeskin finds the clue in the exordium, where Socrates denies that he is a skillful speaker: "Unless, of course, by a skillful speaker they mean one who speaks the truth. If that is what they mean, I would agree that I am an orator, though not after their pattern" (17b). Although Palamedes makes a comparable claim, Seeskin argues that Palamedes was concerned with appearance rather than truth, and that the key to appearance is the use of the argument from probability. According to Seeskin, Socrates does not rely on the argument from probability, whereas this argument permeates the Palamedes. "Again and again, the speaker tries to show that it would be implausible to suppose that anyone in his position did what he is accused of doing. How... (shrink)

This thesis is an argument for the view that there are problems for Modal Reductionism, the thesis that modality can satisfactorily be defined in non-modal terms. -/- I proceed via a case study of David Lewis’s theory of concrete possible worlds. This theory is commonly regarded as the best and most influential candidate reductive theory of modality. Based on a detailed examination of its ontology, analysis and justification, I conclude that it does badly with respect to the (...) following four minimal conditions on a satisfactory reductive theory of modality: that it be (a) genuinely reductive, (b) materially adequate, (c) conceptually adequate and (d) that its justification provides good reason to think it true. -/- These problems for Lewis’s theory are not, I suggest, due to his idiosyncratic conception of possible worlds as concrete entities. Rather, because Lewis’s theory can be seen to represent an important class of structurally similar reductive theories of modality, the problems for Lewis’s theory generalise to problems for these other theories. This suggests that Modal Reductionism is unpromising. In the light of this, the alternative approach to understanding modality, Modal Primitivism, appears more attractive. (shrink)

Today, a new vein of queer Marxist-feminist family-abolitionist theorising is reviving contemporary feminists’ willingness to imagine, politically, what women's liberationists in the 1970s called ‘mothering against motherhood’. Concurrently, the jokey portmanteau ‘momrade’, i.e. mom + comrade, has circulated persistently in the twenty-first century on online forums maintained by communities of mothers and/or leftists. This article asks: what if, in the name of abolishing the family, we took the joke entirely seriously? What makes a ‘mom’ a ‘momrade’, or vice versa? In (...) what ways does the work of reproduction, conceivably, actively participate in class struggles, producing new worlds (and un-producing others)? How do the collective arts of mothering unmake selves? And how does the verb ‘to mother’ work to abolish the present state of things? The chosen point of departure for exploring these questions is the concept of xenohospitality; a term I borrow from Helen Hester – one of the authors of the Xenofeminist Manifesto – who defines it as openness to the alien, a definition I link closely to ‘comradeliness’. Further, the meaning of the term ‘family abolition’, here, is aptly summed up by the formula ‘xenofam ≥ biofam’; to abolish the family is not to destroy relationships of care and nurturance, but on the contrary, to expand and proliferate them. Reflecting on the conditions of possibility for such universally xenofamilial – that is to say, comradely – kin relations, this article implicitly argues for utopia(nism) in feminist kinship studies. It grounds this utopianism, however, in first-hand experiences of informal ‘death doula’ labour. The labour of mothering one's mother is offered as a potential practice of un-mothering oneself and others. In fact, the argument pivots on these auto-ethnographic observations about maternal bereavement, because the event of the author's mother's death interrupted and intruded upon the feminist theorising involved. (shrink)

Ramseyan humility is the thesis that we cannot know which properties realize the roles specified by the laws of completed physics. Lewis seems to offer a sceptical argument for this conclusion. Humean fundamental properties can be permuted as to their causal roles and distribution throughout spacetime, yielding alternative possible worlds with the same fundamental structure as actuality, but at which the totality of available evidence is the same. On the assumption that empirical knowledge requires evidence, we cannot (...) know which of these worlds is actual. However, Lewis also appeals to a range of familiar semantic principles when framing his argument, which leads some authors to suppose that he can also plausibly be interpreted as offering a purely semantic argument for humility in addition. In this paper I grant that these arguments are Lewisian, but argue that Lewis is also committed to a theory of mind that licenses a purely metaphysical argument for humility based on the idea that mental properties supervene on fundamental structure. Given that knowing which x is the F requires knowing that a is the F, the supposition that we could come to know which properties actually occupy the fundamental roles entails differences in mental properties between worlds with the same fundamental structure, violating supervenience. Humility follows right away, without any further epistemic or semantic principles. This argument is immune to almost every way of rebutting the sceptical and semantic arguments; conversely, almost every way of rebutting the metaphysical argument tells equally against the others. (shrink)

My dissertation consists of three essays in the Metaphysics of Modality: In "A Puzzle about Truth and Singular Propositions," I consider two theses that seem to be true and then an argument for the conclusion that they form an inconsistent pair. One thesis is that a proposition that is singular with respect to a given object implies that the object exists. This is so because the proposition predicates something of the object. The other thesis is that some propositions are (...) true with respect to possible worlds in which they do not exist. An example is the negation of the proposition that Socrates is wise. This proposition is true with respect to possible worlds in which Socrates does not exist, but it does not exist in those worlds. ;In "Actualism, Ontological Dependence, and Possible Worlds," I consider Actualism, the doctrine that every possible object is an actual object. Plantinga has argued that the actualist is committed to the existence of unexemplified essences if he analyzes statements of modality by quantifying over possible worlds and over members of their domains. I argue that the actualist is committed to the existence of unexemplified essences even if he paraphrases statements of modality by quantifying only over possible worlds and actual objects. ;In "Possibilism and the Nature of Actuality," I consider Possibilism, the doctrine that there are possible objects that are not actual objects. Possibilism seems to be a coherent ontological doctrine. It is not Meinong's doctrine that there are objects of which it is true to say that there are no such objects. If one fails to distinguish between these two doctrines, then one's attempt to refute Possibilism might amount to an attack on a blatant contradiction. I illustrate this claim by arguing that the distinction between Possibilism and Meinong's doctrine has eluded Plantinga. I then consider the view that Possibilism is a consequence of Lewis's doctrine that 'actual' is an indexical term. I also argue that the sense in which Lewis said that 'actual' is indexical is an esoteric sense of the word, not a sense it ordinarily has. (shrink)

Counterfactuals is David Lewis's 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. Since its original publication in 1973, it has become a classic of contemporary philosophy, and is essential reading for anyone interested in the logic and metaphysics of counterfactuals. The book also includes an appendix of related writings by Lewis.

The main problem with the many‐worlds theory is that it is not clear how the notion of probability should be understood in a theory in which every possible outcome of a measurement actually occurs. In this paper, I argue for the following theses concerning the many‐worlds theory: If probability can be applied at all to measurement outcomes, it must function as a measure of an agent’s self‐location uncertainty. Such probabilities typically violate reflection. Many‐worlds branching does not (...) have sufficient structure to admit self‐location probabilities. Decision‐theoretic arguments do not solve this problem. †To contact the author, please write to: Department of Philosophy, University of Miami, P.O. Box 248054, Coral Gables, FL 33124‐4670; e‐mail: [email protected]. (shrink)

Arguments are advanced that a theory of possible worlds cannot be a theory of meaning for modal statements, And lewis's version of the theory in his "counterfactuals" is used as a particular stalking-Horse. (a) 'possible world', Though used referentially, Is defined in a way that makes it non-Referential, And moreover, The theory does not supply or validate proposals for criteria that individuate worlds; hence the theory seems incomprehensible. (b) the theory yields no useable account of (...) truth-Conditions for modal statements. (c) a conceptualist version of the theory cannot overcome these problems. (d) lewis's similarity theory of possible worlds as a semantics for counterfactuals sustains in many cases (including one he cites) intuitively untrue counterfactuals and rejects many intuitively correct ones. (shrink)

David Lewis’ contemplations regarding divine foreknowledge and free will, along with some of his other more substantial work on modal realism and his counterpart theory can serve as a springboard to a novel solution to the foreknowledge and metaphysical freedom puzzle, namely a proposal that genuine metaphysical freedom is compatible with determinism, which is quite different from the usual compatibilist focus on the compatibility between determinism and moral responsibility. This paper argues that while Lewis opens the doors to such a (...) possibility, in order to fully elucidate a genuinely metaphysical compatibilist account, Lewis’ own counterpart theory must be abandoned in favour of an account of trans-world identity that is theoretically framed by a modified version of Robert Nozick’s closest continuer theory. (shrink)

Lewisian Genuine Realism about possible worlds is often deemed unable to accommodate impossible worlds and reap the benefits that these bestow to rival theories. This thesis explores two alternative extensions of GR into the terrain of impossible worlds. It is divided in six chapters. Chapter I outlines Lewis’ theory, the motivations for impossible worlds, and the central problem that such worlds present for GR: How can GR even understand the notion of an impossible world, (...) given Lewis’ reductive theoretical framework? Since the desideratum is to incorporate impossible worlds into GR without compromising Lewis’ reductive analysis of modality, Chapter II defends that analysis against objections. The rest of the thesis is devoted to incorporating impossible worlds into GR. Chapter III explores GR-friendly impossible worlds in the form of set-theoretic constructions out of genuine possibilia. Then, Chapters IV-VI venture into concrete impossible worlds. Chapter IV addresses Lewis’ objection against such worlds, to the effect that contradictions true at impossible worlds amount to true contradictions tout court. I argue that even if so, the relevant contradictions are only ever about the non-actual, and that Lewis’ argument relies on a premise that cannot be nonquestion- beggingly upheld in the face of genuine impossible worlds in any case. Chapter V proposes that Lewis’ reductive analysis can be preserved, even in the face of genuine impossibilia, if we differentiate the impossible from the possible by means of accessibility relations, understood non-modally in terms of similarity. Finally, Chapter VI counters objections to the effect that there are certain impossibilities, formulated in Lewis’ theoretical language, which genuine impossibilia should, but cannot, represent. I conclude that Genuine Realism is still very much in the running when the discussion turns to impossible worlds. (shrink)

The Forrest-Armstrong argument, as reconfigured by David Lewis, is a reductio against an unrestricted principle of recombination. There is a gap in the argument which Lewis thought could be bridged by an appeal to recombination. After presenting the argument, I show that no plausible principle of recombination can bridge the gap. But other plausible principles of plenitude can bridge the gap, both principles of plenitude for world contents and principles of plenitude for world structures. I conclude that (...) the Forrest-Armstrong argument, when fortified in one of these ways, demands that unrestricted recombination be rejected. The appropriate restriction comes from a consideration of what world structures are possible. I argue that, although there are too many worlds to form a set, for any world, the individuals at that world do form a set. To defend it I invoke a principle of Limitation of Size together with an iterative conception of structure. (shrink)

David Lewis’s arguments against magical ersatzism are notoriously puzzling. Untangling different strands in those arguments is useful for bringing out what he thought was wrong with not just one style of theory about possible worlds, but with much of the contemporary metaphysics of abstract objects. After setting out what I take Lewis’s arguments to be and how best to resist them, I consider the application of those arguments to general theories of properties and relations. The constraints Lewis motivates (...) turn out to yield an argument for concretism about possible individuals that is quite different from the better-known Lewisian arguments for that position. The discussion also touches on the puzzling question of whether things are the way they are because of the properties they have, or are the properties and relations the way they are because of the things that have them. (shrink)

Helen Beebee has recently argued that David Lewis’s account of compatibilism, so-called local miracle compatibilism, allows for the possibility that agents in deterministic worlds have the ability to break or cause the breaking of a law of nature. Because Lewis’s LMC allows for this consequence, Beebee claims that LMC is untenable and subsequently that Lewis’s criticism of van Inwagen’s Consequence Argument for incompatibilism is substantially weakened. I review Beebee’s argument against Lewis’s thesis and argue that Beebee has (...) not refuted LMC and concomitantly has not demonstrated that Lewis’s criticism of the Consequence Argument fails. (shrink)

David Lewis objected to theories that posit necessary connections between distinct entities and to theories that involve a magical grasping of their primitives. In On the Plurality of Worlds, Lewis objected to nondescript ersatzism on these grounds. The literature contains several reconstructions of Lewis’ critique of nondescript ersatzism but none of these interpretations adequately address his main argument because they fail to see that Lewis’ critique is based on broader methodological considerations. I argue that a closer look at (...) his methodology reveals the broader objection he presented against nondescript ersatzism. This objection, I further argue, remains a challenge for the ersatzer who posits structure-less entities as possible worlds. (shrink)

According to David Lewis, a realist about possible worlds must hold that actuality is relative: the worlds are ontologically all on a par; the actual and the merely possible differ, not absolutely, but in how they relate to us. Call this 'Lewisian realism'. The alternative, 'Leibnizian realism', holds that actuality is an absolute property that marks a distinction in ontological status. Lewis presents two arguments against Leibnizian realism. First, he argues that the Leibnizian realist cannot account (...) for the contingency of actuality. Second, he argues that the Leibnizian realist cannot explain why skepticism about one's own actuality is absurd. In this paper, I mount a defense of Leibnizian realism. (shrink)

This note is a reply to margery bedford naylor's "a note on david lewis's realism about possible worlds" . naylor asks why, if we accept david lewis's argument for real possible worlds , we should not accept an analogous argument for impossible worlds. i argue that the latter argument is invalid on the modal realist account of possibility and thus has no force for an adherent of lewis.

Einstein argued in his latter years that the intelligibility of the world was in the nature of a miracle, and that in no way could one have expected a priori such a high degree of order; this is why he rejected the atheist, positivist standpoint, and believed in a Spinozist God. Einstein's argument, however, is essentially a form of the ?argument from design? for a personal God based on the existence of beautiful, mathematically simple laws of nature; that (...) physical order is a unique, improbable alternative compared to the infinite number of chaotic universes that might have existed. Einstein, in his early manhood, was a Humean, but in later years, as he moved toward Spinoza, from phenomenalism to noumenalism, he clearly rejected Hume's restriction of probable inferences to observed sequences. Darwin's arguments against biological design did not apply to Einstein's argument, because the laws of physics are not the outcome of any cumulative struggle for existence and natural selection. Perhaps the beautiful simplicity of basic physical laws helps account for the fact that relatively more physicists than biologists or psychologists hold to a theistic standpoint. Einstein's finite universe would have seriously weakened the argument that life, though infinitely improbable, would have been realized in an infinite world. But in any case, Einstein would have regarded ?emergence? theories of life as irrational. In accordance with the principle of identity of Emile Meyerson, the epistemologist whom he most respected, it would have followed that the occurrence of consciousness and intelligence was grounded in a God with those attributes, and that theism was consequently the basis for scientific knowledge. (shrink)

Building on the pioneer work of Lycan (1988, 1991a and b, 1994) and Yagisawa (1988), this paper aims to set out in a comprehensive way the case for the view that Lewis' analyses of modality in terms of quantification over worlds and counterparts fail to be genuinely reductive. This involves bringing together elements of the case which have hitherto remained unconnected, motivating some of those elements in new and more decisive ways, and bolstering them by considering a range of (...) objections that have been levelled against them (including recent ones by Stalnaker and Divers). The paper proceeds as follows. Section 1 introduces Lewis' analyses of de dicto and de re modality. Section 2 argues that, as deployed by Lewis, the notion of ‘world’ is modal in nature. This is because the analyses he proposes are extensionally adequate only if he takes ‘world’ to mean possible-as-opposed-to-impossible world. An important response to this charge is simply to deny that there are impossible worlds. Section 3 considers and rejects Lewis' argument for that claim, while section 4 argues that a prima facie case can be made for the claim that Lewis is in fact committed to the existence of impossible worlds. (shrink)

An objection is presented to Lewis’s analysis of counterfactual conditionals in terms of relative closeness of possible worlds. The objection depends on no special assumptions about the ‘closer-than’ relation. The argument also casts doubt on Lewis’s claim that Antecedent Strengthening fails for counterfactuals.

The goal of this paper is to raise a novel objection to Lewis’s modal realist epistemology. After reformulating his modal epistemology, I shall argue that his view that we have necessary knowledge of the existence of counterparts ends up with an absurdity. Specifically, his analogy between mathematical knowledge and modal knowledge leads to an unpleasant conclusion that one’s counterpart exists in all possible worlds. My argument shows that if Lewis’s modal realism is true, we cannot know what (...) is possible. Conversely, if we can know what is possible, his modal realism is false. In the remainder of the paper, I shall consider and block possible objections to my argument. (shrink)

The paper deals with such a modification of genuine modal realism as to accommodate impossible worlds into its ontology. First of all, the theory of modal realism is presented. Next, several motivations for the acceptance of impossible worlds are adduced. Further, Lewis’s argument against impossible worlds is presented. It is argued that the argument can be weakened by rejection of one of its premises. Finally, two objections against the proposal are countered. Although my strategy accounts (...) for the Opinion concerning the impossible, it allegedly violates another Opinion which conceives the reality classical. It seems, however, that there is no no-question-begging reason to think that reality is classical. How can we know, after all, which logic describes reality? Without a definite answer to the question, the incredibility objection then simply collapses into a statement of a possibilist dogma. (shrink)

This thesis examines the alethic modal concepts of possibility and necessity. It is argued that one cannot do justice to all our modal talk without possible worlds, i.e., complete ways that a cosmos might have been. I argue that not all of the proposed applications of possible worlds succeed but enough remain to give one good theoretical reason to posit them. The two central problems now are: What feature of reality makes correct alethic modal claims true (...) and What are possible worlds? ;David Lewis makes possible worlds be concretely existing universes. Unfortunately, I show Lewis's account involves set-theoretic, ethical, inductive and probabilistic paradoxes, and commits Lewis to an objectionable form of primitive modality that governs the choice of the counterpart relation. The most promising contemporary alternatives to Lewis's theory have been the worlds of Adams and Plantinga constructed out of Platonic entities such as maximal collections of consistent propositions. However, these approaches fail to provide a satisfactory answer to the question of what makes true modal claims true. I also criticize some alternative accounts. ;Finally, I discuss and combine two historical approaches. The first is an Aristotelian approach that says a non-actual event is possible is to say that some actual substances could have initiated a causal chain that could lead up to the event in question. However, it can be shown that some plausible global possibility claims can be made true on this account only if there is a necessarily existent first cause capable of initiating very different universes. On the other hand, Leibniz made possible worlds be ideas in the mind of an omniscient necessarily existent deity. Leibniz fails to explain what it is that makes these possible worlds possible, but if we were willing to combine his story with the conclusion drawn from the Aristotelian one, we could get the following story: Possible worlds are ideas in the mind of an omniscient deity and what makes them possible is that this deity has the Aristotelian capability of initiating causal chains that can lead to them being actualized. (shrink)

David Lewis [1973] offers a possible worlds approach to a theory of counterfactuals. He attempts to specify necessary and sufficient conditions according to which a given counterfactual is true or false. This MA Thesis surveys Lewis's theory of counterfactuals in detail. Although for the most part I defend Lewis's account from several objections, in the final chapter I reason that his theory is susceptible to skepticism, which threatens any philosophical theory that relies on Lewis's theory (...) to distinguish between non-paradigmatically true and false counterfactuals. As for the more sympathetic portion of my project, while I show how Lewis's canonical account cannot handle some paradigmatically false counterfactuals--viz., those containing true components--I try to repair his analysis in the spirit of Alan Penczek [1997]. I then discuss Lewis's extension or enhancement to his original theory, which he gives in order to foil an objection advanced by Kit Fine [1975] and Jonathan Bennett [1984]. Finally, I outline and raise several worries inherent in Bennett's rival theory. As for the less then sympathetic section of this paper, I exploit arguments put forward by G. Lee Bowie [1979] as well as by Daniel Krasner and Mark Heller [1994], which are designed to undermine any systematic procedure to circumscribe Lewis's crucial three-place comparative similarity relation between possible worlds. (shrink)

In The Untamed God (2003), Jay Wesley Richards defends what he calls “theological essentialism,” which affirms God’s essential perfections but also recognizes contingent properties in God. This idea places Richards’s view in the vicinity of Charles Hartshorne’s dipolar theism. However, Richards argues that Hartshorne’s modal theory suffers from the defects that it abandons the principle ab esse ad posse, makes nonsense of our counter-factual discourse, and can only be expressed by C. I. Lewis’s S4, although for certain purposes Hartshorne needs (...) the stronger S5. Richards, however, fails to realize that Hartshorne’s theory involves two concepts of necessity—necessity as what is common to every possible world-state and necessity as it pertains to the unalterability of the past. While questions remain about Hartshorne’s theory, Richards’s arguments against it are unsuccessful. Most importantly, Richards uncritically accepts the concept of possible worlds as a basis for his critique, but Hartshorne’s arguments cast doubt on the coherence of this idea. Possible worlds provide anything but a firm foundation on which to make sense of either theological essentialism or Hartshorne’s panentheistic dipolar theism. (shrink)

David Lewis holds that a single possible world can provide more than one way things could be. But what are possible worlds good for if they come apart from ways things could be? We can make sense of this if we go in for a metaphysical understanding of what the world is. The world does not include everything that is the case—only the genuine facts. Understood this way, Lewis's “cheap haecceitism” amounts to a kind of metaphysical (...) anti-haecceitism: it says there aren't any genuine facts about individuals over and above their qualitative roles. (shrink)

David Lewis is widely known for maintaining the bizarre thesis known as genuine modal realism (hereafter, modal realism). He argued for modal realism on grounds of serviceability in On the Plurality of Worlds. However, earlier in Counterfactuals, he proposed a different kind of argument: from talk of ways things might be to possible worlds. In this paper, I examine the evolution of the latter argument in Lewis’s thought and evaluate its place in his overall case (...) for modal realism, especially in light of the alternative theory of modality known as magical ersatzism. I argue that Lewis turns the argument on its head in his critique of magical ersatzism, but that his later commitment to Ramseyan humility subjects him to a similar criticism. Therefore, the argument is, ultimately, a poisoned pawn for Lewis. (shrink)

This paper argues for a possible-worlds interpretation of the arguments marshalled by Socrates against Protagoras in Plato’s Theaetetus. Specifically, it reads Protagoras’ position as implying a limited form of modal realism, and evaluates both the self-refutation sequence at 170a–71d and the Future Argument at 177c–9c on the basis of this reading. It emerges that Socrates’ project is only partly successful: while the three main arguments of the self-refutation sequence force Protagoras into ever more awkward and metaphysically top-heavy (...) positions, and the Future Argument is psychologically compelling, these arguments do not force a collapse of the relativist position. Protagoras can still defend himself, though the cost is high. (shrink)

In this paper, I argue that all expressions for abstract objects are meaningless. My argument closely follows David Lewis’ argument against the intelligibility of certain theories of possible worlds, but modifies it in order to yield a general conclusion about language pertaining to abstract objects. If my Lewisian argument is sound, not only can we not know that abstract objects exist, we cannot even refer to or think about them. However, while the Lewisian argument (...) strongly motivates nominalism, it also undermines certain nominalist theories. (shrink)

In this paper, I examine the putative incompatibility of three theses: (1) Haecceitism, according to which some maximal possibilities differ solely in terms of the non-qualitative or de re possibilities they include; (2) Modal correspondence, according to which each maximal possibility is identical with a unique possible world; (3) Counterpart theory, according to which de re modality is analyzed in terms of counterpart relations between individuals. After showing how the modal realism defended by David Lewis resolves this incompatibility by (...) rejecting modal correspondence, I defend modal correspondence and develop an alternative strategy for reconciling these theses. Specifically, I examine Lewis’s arguments against non-qualitative counterpart theory and undermine them by developing a novel version of non-qualitative counterpart theory that appeals to a metaphysics of bare particulars. I then indicate how this version of non-qualitative counterpart theory accommodates both haecceitism and modal correspondence. (shrink)

I reject Norton and Earman's hole argument that spacetime substantivalism is incompatible with determinism. I reconcile these both technically and philosophically. There is a technical definition of determinism that is not violated by pairs of models of the kind used in the hole argument. And technicalities aside, the basic idea of determinism is not violated if we claim that at most one of the two models represents a possible world. This claim can be justified either by metrical (...) essentialism, or by denying transworld identity for points: I prefer the latter. (shrink)

Eduardo García-Ramírez has offered a reductio of the counterfactual analysis of causation. The argument purportedly shows that, given a natural generalization of Lewis’ semantics for counterfactuals, statements expressing the existence of causal dependence across worlds are satisfiable. The aim of the present paper is twofold. In the first part, I show that the purported reductio is flawed, as it relies on an overly strong construal of the semantics for counterfactuals. In particular, it is assumed that we can assign (...) a degree of similarity to any given pair of possible worlds. As it turns out, that assumption reduces to the thesis that the relations of comparative similarity featured in the standard semantics for counterfactuals define an interval scale of measurement on the set of all possible worlds. It will be argued that such a thesis is incompatible with a viable understanding of comparative similarity. The second part of the paper is devoted to a new proof of the possibility of trans-world causation. Nevertheless, the new proof does not amount to a reductio of Lewis’ account of causation per se, but rather of the conjunction of several substantive theses (the counterfactual analysis of causation, modal plenitude, the existence of mereological sums and the best theory account of natural laws). (shrink)

It is difficult to wander far in contemporary metaphysics without bumping into talk of possible worlds. And reference to possible worlds is not confined to metaphysics. It can be found in contemporary epistemology and ethics, and has even made its way into linguistics and decision theory. What are those possible worlds, the entities to which theorists in these disciplines all appeal? This paper sets out and evaluates a leading contemporary theory of possible (...) class='Hi'>worlds, David Lewis's Modal Realism. I note two competing ambitions for a theory of possible worlds: that it be reductive and user-friendly. I then outline Modal Realism and consider objections to the effect that it cannot satisfy these ambitions. I conclude that there is some reason to believe that Modal Realism is not reductive and overwhelming reason to believe that it is not user-friendly. (shrink)

Those who object to David Lewis' modal realism express qualms about philosophical respectability of the Lewisian notion of a possible world and its correlate notion of an inhabitant of a possible world. The resulting impression is that these two notions either stand together or fall together. I argue that the Lewisian notion of a possible world is otiose even for a good Lewisian modal realist, and that one can carry out a good Lewisian semantics for modal discourse (...) without Lewisian possible worls. I do so by generalizing Lewis' own idea that restrictions on quantification come and go with the pragmatic wind and relativizing possible worlds as shifting domains of discourse. I then suggest a way to soften the infamous incredulous stare. (shrink)

First we have individual variables, as usual in first-order logics. (We do not have individual constants, but this is a minor point.) The propositional logic LP has justification constants, but in FOLP these are generalized to allow individual variables as arguments. Thus we have as justification constants c, c(x), c(x, y), . . . . Similarly LP has justification variables, but in FOLP these can be parametrized with individual variables p, p(x), p(x, y), . . . . To keep terminology (...) in line with past papers, we will still refer to things as justification constants and justification variables, even though they have structure to them. As in LP, justification terms are built up from justification constants and justification variables using ·, +, ! as usual. In addition there is a new constructor, genx, introduced by Artemov, and there is one further new constructor, exsx, introduced in this paper. If t is a justification term and x is an individual variable, genxt and exsxt are justification terms. An individual variable x is free in a justification term unless it is bound by genx or exsx. More specifically, the free variables of p(x, y, . . .) and of c(x, y, . . .) are {x, y, . . .}, the free variables of s · t and of s + t are the free variables of s together with the free variables of t, the free variables of !s are the free variables of s, and the free variables of genxt and of exsxt are the free variables of t except for x. Formulas are built up from atomic formulas, including ⊥, in the way standard in first-order logic, together with the additional formation rule: t:X is a formula provided t is a justification term, X is a formula, and all free variables of X occur in t. We assume ⊃, ⊥, and ∀ are basic, with other connectives and quantifier defined. The axiomatization used here is a combination of an LP axiomatization and a standard axiomatization of first-order logic, together with a version of the Barcan formula, and one additional axiom that corresponds to the converse Barcan formula.. (shrink)

_ Source: _Page Count 19 The theory of possible worlds has been minimally employed in the field of theory and philosophy of history, even though it has found a place as a tool in other areas of philosophy. Discussion has mostly focused on arguments concerning counterfactual history’s status as either useful or harmful. The theory of possible worlds can, however be used also to analyze historical writing. The concept of textual possible worlds offers an (...) interesting framework to work with for analyzing a historical text’s characteristics and features. However, one of the challenges is that the literary theory’s notion of possible worlds is that they are metaphorical in nature. This in itself is not problematic but while discussing about history, which arguably deals with the real world, the terminology can become muddled. The latest attempt to combine the literary and philosophical notions of possible worlds and apply it to historiography came from Lubomír Doležel in his _Possible Worlds of Fiction and History: The Postmodern Stage_. I offer some criticism to his usage of possible worlds to separate history and fiction, and argue that when historiography is under discussion a more philosophical notion of possible worlds should be prioritized over the metaphorical interpretation of possible worlds. (shrink)

This article aims to provide a new ontological argument for the existence of God. A specific ‘modal’ version of the ontological argument—termed the Modal Realist Ontological Argument—is formulated within the modal realist metaphysical framework of David K. Lewis, Kris McDaniel and Philip Bricker. Formulating this argument within this specific framework will enable the plausibility of its central premise (i.e., the ‘Possibility Premise’) to be established, and allow one to affirm the soundness of the argument—whilst warding (...) off two oft-raised objections against this type of natural theological argument. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:EMBODIED HUMAN AGENTS INHABITING A MATERIAL WORLD? CHARLES T. HUGHES Chapman University Orange, California I. /n;troduction HE CONCEPT of a "logically possible world" has roven useful in the investigation of issues within many ranches of philosophy, including the philosophy of religion.1 Since this paper includes an analysis of one "possible worlds" objection to Christian theism, based upon the problem of evil, it will prove useful to (...) preface my discussion with a paragraph which summarizes some of the ideas important to the logic of possible worlds. Each logically possible world contains a complete set of compossible facts, which includes the past, present, and future of its objects, properties, and relations. Those complete sets of compossible facts, each of which describes the way the actual world could have been, have in common the truth of all logically necessary propositions (for example, 2 +2 = 4, "Circles cannot be squared "), and the falsity of all logically impossible propositions (for example, 2 +6 = 7, " Circles can be squared"), but differ in their truth values with respect to at least some logically contingent propositions (for example, "Elephants exist" is true in one or more possible worlds but false in all others, and "Unicorns exist " is true in one or more possible worlds but false in all others). An impossible world includes an affirmation of the falsity of at least one necessary proposition (for example,,.._,(2 +2 = 4)), and/or affirms the truth of at least one logical1 See Alvin Plantinga, The Nature of Necessity (Oxford: Clarendon Press, 1974), chapters IX and X. 389 390 CHARLES T. HUGHES ly impossible proposition (for example, " Logically necessary propositions are false in all possible worlds ").2 The actual world, which is our world, is that complete set of compossible propositions which describe the way things actually are. The actual world, therefore, differs from other possible worlds in that all of its contingent propositions correspond to the past, present, and future of all of the objects, properties, and relations which actually obtain. There is an on-going debate about the nature and ontological status of possible worlds and their objects.3 The purpose of this paper is to analyze and reject a particular "possible worlds" objection to Christian theism, based upon the problem of evil, which is not frequently discussed in philosophical literature. The problem is this : If God must actualize a possible world in order to provide human agents with the initial stage of existence they require to develop freely as rational, moral, and religious beings, who choose their own destinies, why did God not create them as incorporeal agents within an immaterial world which would, by its very nature, eliminate the physical dimension of evil and suffering which plagues the actual world? For it seems, prima facie, that God could have realized his purposes by actualizing an immaterial world, populated with human-like incorporeal agents, thereby avoiding all of the terrible evil and suffering made possible by physicality. Therefore, the existence of the actual physical world, with all its evil and suffering, is evidence against the existence of God.4 In order to show that the previously stated objection from evil could pose a genuine threat to theism, I will first identify some of my important assumptions in this paper, and then outline particular Christian ideas to determine how the " possible worlds " 2 For an argument that some impossible propositions are not self-contradictory, see Linda Zagzebski, " What If the Impossible Had Been Actual," in Michael D. Beatty, ed., Christian Theism aml the Problems of Philosophy (Notre Dame: University of Notre Dame Press, 1990), pp. 165-183. a Compare, for example, the positions of D. M. Armstrong, A Combinatorial Theory of Possibility (Cambridge: Cambridge University Press, 1989) and D. Lewis, On the Plurality of Worlds (Oxford: Blackwell, 1986). 4 Some interesting discussion of this type of problem can be found in Austin Farrer, Love Almighty and Ills Unlimited (London: Collins, 1962), pp. 69-76. EMBODIED HUMAN AGENTS 391 objection to Christian theism could arise in the first place. After that, I will discuss the nature of the " possible worlds " objection and how, in principle, it might be rebutted by theists who possess a great amount of... (shrink)

This work argues for the need to close the gap between the fields of the philosophy of religion and religious studies. Thomas A. Lewis takes up what, in recent years, has often been seen as a fundamental reason for excluding religious ethics and philosophy of religion from religious studies: their explicit normativity. Against this presupposition, Lewis argues that normativity is pervasive--not unique to ethics and philosophy of religion--and therefore not a reason to exclude them from religious studies. He bridges more (...) philosophical and historical subfields by arguing for the importance of history to the philosophy of religion. He considers the future of religious ethics, explaining that the field as whole should learn from the methodological developments associated with recent work in comparative religious ethics and 'comparative religious ethics' should no longer be conceived as a distinct subfield. The concluding chapter engages broader, post-9/11 arguments about the importance of studying religion, arguing that prominent contemporary notions of 'religious literacy' actually hinder our ability to grasp the significance of religion and impact in the world today. (shrink)

The canonical version of possible worlds semantics for story prefixes is due to David Lewis. This paper reassesses Lewis's theory and draws attention to some novel problems for his account.

The author--a Danish philosopher influenced by Moore, the later Wittgenstein, and C. I. Lewis--lays bare three fundamental rules of "informal logic" implicit in any description of empirical reality. They are: psychological expressions cannot be applied independently of the personal pronouns, personal pronouns cannot be applied independently of names of ordinary things, and names of ordinary things cannot be applied independently of words expressing possibility of action. A number of important consequences are drawn: in particular, that certain traditional philosophical problems--such as (...) the existence of the external world and the future validity of physical laws--cannot be properly formulated; and that the description of nature cannot afford any argument for psychological determinism. A stimulating book. --T. L. M. (shrink)

Well‐known arguments for atheism have been grounded on the alleged lack of morally justifying reasons to permit particular moral and natural evils and on the thesis that God would have to create the best possible world. After discussing obstacles to the suggestion that there is a best of all possible worlds, I examine the prospects for responding to these atheistic arguments by exploring the case for our own world's being the best of all possible worlds (...) against the backdrop of the multiverse hypothesis – an intriguing claim about the partitioned structure of reality that has been receiving serious and recent attention in philosophy and physics. (shrink)