Among the many possible approaches to dealing with logical omniscience, I consider here awareness and impossible worlds structures. The former approach, pioneered by Fagin and Halpern, distinguishes between implicit and explicit knowledge, and avoids logical omniscience with respect to explicit knowledge. The latter, developed by Rantala and by Hintikka, allows for the existence of logically impossible worlds to which the agents are taken to have access; since such worlds need not behave consistently, the agents’ knowledge is fallible relative (...) to logical omniscience. The two approaches are known to be equally expressive in propositional systems interpreted over Kripke semantics. In this paper I show that the two approaches are equally expressive in propositional systems interpreted over Montague-Scott (neighborhood) semantics. Furthermore, I provide predicate systems of both awareness and impossible worlds structures interpreted on neighborhood semantics and prove the two systems to be equally expressive. (shrink)

This essay examines some of Derrida’s most famous ‘possible-impossible’ aporias, including his discussions of giving, hospitality, forgiveness, and mourning. He argues that the condition of the possibility of such themes is also, and at once, the condition of their impossibility. In order to reveal the shared logic upon which these aporias rely, and also to raise some questions about their persuasive efficacy, it will be argued that of the two polarities evoked by each of his possible-impossible aporias, the (...) ‘impossible’ term of the opposition invariably posits a separation between “two radical singularities”, or in somewhat more controversial terms, between a self and an other. While Derrida emphasises this ‘impossible’ aspect of giving, hospitality, forgiveness, etc., Merleau-Ponty’s abiding emphasis upon the chiasmic intertwining of self and other provides the resources to challenge this emphasis, and even to reverse it. While Merleau-Ponty rarely directly addresses the kind of aporias that concern Derrida, his chiasmic account of embodiment, and his emphasis upon the body-subject’s propensity to seek an equilibrium with its environment, better accounts for the ‘possible’ side of the aporias that Derrida describes. In the process, it will be argued that Merleau-Ponty’s later philosophy also allows for a more politically efficacious idea of responsibility towards the other than the position to which Derrida is tacitly committed. (shrink)

In this paper, I investigate whether we can use a world-involving framework to model the epistemic states of non-ideal agents. The standard possible-world framework falters in this respect because of a commitment to logical omniscience. A familiar attempt to overcome this problem centers around the use of impossible worlds where the truths of logic can be false. As we shall see, if we admit impossible worlds where “anything goes” in modal space, it is easy to model extremely non-ideal agents (...) that are incapable of performing even the most elementary logical deductions. A much harder, and considerably less investigated challenge is to ensure that the resulting modal space can also be used to model moderately ideal agents that are not logically omniscient but nevertheless logically competent. Intuitively, while such agents may fail to rule out subtly impossible worlds that verify complex logical falsehoods, they are nevertheless able to rule out blatantly impossible worlds that verify obvious logical falsehoods. To model moderately ideal agents, I argue, the job is to construct a modal space that contains only possible and non-trivially impossible worlds where it is not the case that “anything goes”. But I prove that it is impossible to develop an impossible-world framework that can do this job and that satisfies certain standard conditions. Effectively, I show that attempts to model moderately ideal agents in a world-involving framework collapse to modeling either logical omniscient agents, or extremely non-ideal agents. (shrink)

This chapter contains sections titled: Logical Possibility and Impossibility J. L. Mackie's Argument Interim Verdict: ‘Not Proved’ Suggested Reading.

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

In this paper I propose a formalization, using modal logic, of the notion of possibility that phoneticians use when they judge speech sounds to be possible or impossible. I argue that the most natural candidate for a modal logic of phonetic possibility is the modal system T.

Modal realism -- Time, space, world -- Existence -- Actuality -- Modal realism and modal tense -- Transworld individuals and their identity -- Existensionalism -- Impossibility -- Proposition and relief -- Fictional worlds -- Epistemology.

A. Collins once argued that time travel is only imaginable if we relate the "event" out of context. John Hospers argues that it is logically possible for an iron bar to float in water even if it is actually (empirically) impossible. My point in this piece is that Hospers relies on viewing the floating out of context, in Walt Disney fashion; but that is no way to establish any kind of possibility. I also discuss "conceivability", a term frequently used (...) either to clarify logical possibility or to interchange for the same. I argue that it cannot do either. (shrink)

Possible worlds have found many applications in contemporary philosophy: from theories of possibility and necessity, to accounts of conditionals, to theories of mental and linguistic content, to understanding supervenience relationships, to theories of properties and propositions, among many other applications. Almost as soon as possible worlds started to be used in formal theories in logic, philosophy of language, philosophy of mind, metaphysics, and elsewhere, theorists started to wonder whether impossible worlds should be postulated as well. In many applications, possible (...) worlds face limitations that can be dealt with through postulating impossible worlds as well. This chapter examines some of the uses of impossible worlds, and philosophical challenges theories of impossible worlds face. (shrink)

A strong impossibility is a situation that is epistemically, but not metaphysically, possible. Opponents of strong impossibilities (including Chalmers, Jackson and Stalnaker) have argued that we have “overwhelming reason” to reject and “very little” or “no reason” to think that such impossibilities exist. This partial draft argues that there are strong impossibilities and (very briefly) discusses the manner in which the existence of strong impossibilities is related to some much-discussed arguments in the philosophy of conscious (...) experience. (The full version of the paper will ultimately include a reply to the most significant argument against strong impossibilities, and a (slightly) more involved discussion of the relevance of all of this to issues in the philosophy of conscious experience.). (shrink)

In traditional semantics for classical logic and its extensions, such as modal logic, propositions are interpreted as subsets of a set, as in discrete duality, or as clopen sets of a Stone space, as in topological duality. A point in such a set can be viewed as a "possible world," with the key property of a world being primeness—a world makes a disjunction true only if it makes one of the disjuncts true—which classically implies totality—for each proposition, a world either (...) makes the proposition true or makes its negation true. This chapter surveys a more general approach to logical semantics, known as possibility semantics, which replaces possible worlds with possibly partial "possibilities." In classical possibility semantics, propositions are interpreted as regular open sets of a poset, as in set-theoretic forcing, or as compact regular open sets of an upper Vietoris space, as in the recent theory of "choice-free Stone duality." The elements of these sets, viewed as possibilities, may be partial in the sense of making a disjunction true without settling which disjunct is true. We explain how possibilities may be used in semantics for classical logic and modal logics and generalized to semantics for intuitionistic logics. The goals are to overcome or deepen incompleteness results for traditional semantics, to avoid the nonconstructivity of traditional semantics, and to provide richer structures for the interpretation of new languages. (shrink)

Using yet untapped resources from moral and political philosophy, this book seeks to answer the question of whether an all good God who is presumed to be all powerful is logically compatible with the degree and amount of moral and natural evil that exists in our world. It is widely held by theists and atheists alike that it may be logically impossible for an all good, all powerful God to create a world with moral agents like ourselves that does not (...) also have at least some moral evil in it. James P. Sterba focuses on the further question of whether God is logically compatible with the degree and amount of moral and natural evil that exists in our world. The negative answer he provides marks a new stage in the age-old debate about God's existence. (shrink)

Throughout his whole work, Wittgenstein seizes on a distinction between logical and physical possibility, and impossibility. Despite this continuity and although, Wittgenstein brings in this distinction in various contexts and from different vantage points, he often solely brushes over it without elaborating in detail. In the so-called Big Typescript, however, he dedicates himself not only to the distinction between logical and physical possibility but also to the distinction between logical possibility and impossibility (...) in particular investigations. In the course of these investigations, another aspect arises and is tossed and turned repeatedly by Wittgenstein – namely, the place of “imaginability” in these considerations. On the basis of three focussed chapters in the Big Typescript, I argue that “imaginability” as an utterance of the form “being able to imagine ‘what it would be like’” can be allocated the place of a criterion for logical possibility. To this end, I will first outline the chapters 96., 27. and 26. in one section each. Although in these chapters, Wittgenstein only indicates rather than claiming explicitly “imaginability” to be a criterion for logical possibility, I will discuss in the last section how this conclusion can be drawn by combining the results of the previous sections. (shrink)

In this paper I explore informationalism, a pragmatic theory of modality that seems to solve some serious problems in the familiar possible worlds accounts of modality. I view the theory as an elaboration of Stalnaker's moderate modal realism, though it also derives from Dretske's semantic theory of information. Informationalism is presented in Section 2 after the prerequisite stage setting in Section 1. Some applications are sketched in Section 3. Finally, a mathematical model of the theory is developed in Section 4.How (...) many times have I said to you that when you have eliminated the impossible, whatever remains, however improbable, must be the truth? (Arthur Conan Doyle)You've put me in an impossible situation. (Anonymous)[N]othing we imagine is absolutely impossible. (David Hume). (shrink)

This text is dedicated to defend the thesis of the impossibility of morals. For this, it discusses different positions concerning morality, like the naturalistic position of Adriano Naves de Brito and the existentialist position of Zelijko Loparic, concerning to identifying each other from the point of view of the defense of an affi rmative position on morals. The purpose of the text is to defend the negative position. From it, doesn’t make any sense defending the possibility of morals, (...) because human beings are morally disqualifi ed. It says that, once moral is an issue that ought to be observed by people in all situations, there is no possibility for the human beings to observe moral obligations. What determines the impossibility of genuine moral behavior is the moral and sensitive worthlessness of the human condition, originally subjected to suffering and countless unfavorable factors to the realization of morals. Key words: negative ethics, naturalism, existentialism. (shrink)

In his natural philosophy, John Buridan reinterprets Aristotelian conceptions of necessity using a framework derived from his logical writings. After a discussion of Buridan’s account of varieties of necessity, in this paper I shall approach some interpretative uses of that account where two natural philosophical concerns are involved. The first is connected with the relationship of modality and time in a question from the first book of his commentary to De Generatione et Corruptione addressing a consequence from possibilities (...) of alteration to possibilities of generation. The content of that question hinges on the metaphysical connection between alteration and substantial changes. In the third section, I shall explore a quasi-definition of causal necessity and contingency Buridan discusses in the second book of his commentary to the Physics. Buridan’s discussion of alternative descriptions of causal necessity and contingency in that context reveals competing pictures of the role of essences in causal explanation associated with Avicenna and Averroes respectively. (shrink)

One response to the problem of logical omniscience in standard possible worlds models of belief is to extend the space of worlds so as to include impossible worlds. It is natural to think that essentially the same strategy can be applied to probabilistic models of partial belief, for which parallel problems also arise. In this paper, I note a difficulty with the inclusion of impossible worlds into probabilistic models. Under weak assumptions about the space of worlds, most of the (...) propositions which can be constructed from possible and impossible worlds are in an important sense inexpressible; leaving the probabilistic model committed to saying that agents in general have at least as many attitudes towards inexpressible propositions as they do towards expressible propositions. If it is reasonable to think that our attitudes are generally expressible, then a model with such commitments looks problematic. (shrink)

Islamic theological contradictions are metaphysical contradictions as opposed to logical and semantic ones. I shall demonstrate that if these theological contradictions are tolerable on the theoretical account of metaphysical dialetheism, then logical space, despite being the space of all possibilities, does not accommodate them in virtue of Chalmers’s ‘deep epistemic possibility’. To resolve this issue, I offer a recalibration of the modal concept of possibility. Doing so would redraw a demarcation between what is possible and (...) what is not. Consequently, we can expand logical space, so it is properly inclusive of all possibilities, including metaphysical dialetheism. Expanding logical space in this way would repudiate Chalmers’s ‘deep epistemic possibility’ and make room for Islamic theological contradictions. (shrink)

In this thesis, I develop a nonreductive and general conception of potentiality, and explore the prospects of a realist account of possibility based on this account of potentiality. Potentialities are properties of individual objects; they include dispositions such as fragility and abilities such as the ability to play the piano. Potentialities are individuated by their manifestation alone. In order to provide a unified account of potentialities, I argue in chapter 2 that dispositions, contrary to philosophical orthodoxy, are best understood (...) in terms only of their manifestations (as disposi- tions to ...), rather than in terms of a stimulus and a manifestation condition (as dispositions to ... if ...). Chapter 3 provides some preliminary motivation for a nonreductive and gen- eral account of potentiality, and chapter 4 develops such an account. The guiding question is how far the notion of potentiality can be extended from the initial ex- amples of familiar dispositions and abilities, and it is argued that it can be extended very far. Various features of potentialities are explored, among them extrinsicality, iterations of potentiality, and the behaviour of potentiality with regard to logical equivalence. In chapter 5, the account is set to work in providing the outlines and a defense of a potentiality-based account of possibility. The basic idea of such an account is that it is possible that p just in case some thing has a potentiality for p. The account is defended against the objection that there may not be enough potential- ities to ground all the possibilities that there are. Finally, in chapter 6, a logic of potentiality is formulated and the logic of possibility derived from it, showing that the potentiality-based account of possibility is formally adequate: it provides pos- sibility with the formal features that modal logicians have studied. I conclude that the proposed account of possibility is a promising research programme. (shrink)

In ‘The Turning Point in Philosophy’ Moritz Schlick expressed the following view: ‘Everything is knowable which can be expressed, and this is the total subject matter concerning which meaningful questions can be raised. There are consequently no questions which are in principle unanswerable, no problems which are in principle insoluble.’ I will refer to this as Schlick's principle, although it is shared by many others. What it amounts to is the view that all meaningful questions can be answered by rational (...) procedures, that is by logical argument or appeal to evidence. It is this view which I wish to challenge, at the same time relating what I have to say to belief in God. For it follows from Schlick's principle that provided the question ‘Does God exist?’ can be meaningfully asked, it is in principle possible to answer it either affirmatively or negatively. Having done so, we would then know, and not merely believe, that God does or does not exist. I will try to show that provided the question ‘Does God exist?’ can be meaningfully asked, no such consequence need be taken to follow. (shrink)

One skeptical strategy against A’s claim to know that P is to hold that it is logically possible for someone to have the same “base” for P as A does in spite of its not being true that P. Philosophical replies have focussed on showing that these are not genuine possibilities. Whether they are can be an interesting question of metaphysics, but it is argued in this paper that this metaphysical discussion is not the proper focus for an assessment (...) of skepticism. Even if there are the odd logical possibilities, they do not suffice to warrant skeptical doubts. Rather, there has to be good reason to think that there is a genuine chance of the alleged possibility obtaining. This requirement cannot be satisfied generically, and that is what is wrong with generic skepticism. (shrink)

I call attention to the following theses concerning possibility. 1) Anything that has become actual must have been possible in the period of time immediately preceding its actualization. 2) The logically possible is a conception, and conceptions exist within the mind. 3) The possible is not a mere name. 4) The possible is not a mental entity and that alone. 5) Every possibility, whether mental entity or not must be, or image, an ontological entity, real although not actual. (...) 6) For all we know logical possibility is the sufficient condition of ontological possibility. 7) Philosophers who lack the category of ontological possibility nonetheless refer to it as an implicit, if hidden, feature of their systems. 8) In some part of the period of time preceding its actualization, an ontological possibility becomes a nascent actuality, and external consistency a necessary condition for nascency. 9) The rise or fall of energy level through directed energy vectors, on human and nonhuman levels, is the third condition for the actualizing of possibilities, or for their failure to actualize. (shrink)

Gaining information can be modelled as a narrowing of epistemic space . Intuitively, becoming informed that such-and-such is the case rules out certain scenarios or would-be possibilities. Chalmers’s account of epistemic space treats it as a space of a priori possibility and so has trouble in dealing with the information which we intuitively feel can be gained from logical inference. I propose a more inclusive notion of epistemic space, based on Priest’s notion of open worlds yet which (...) contains only those epistemic scenarios which are not obviously impossible. Whether something is obvious is not always a determinate matter and so the resulting picture is of an epistemic space with fuzzy boundaries. (shrink)

It is widely assumed that sense perception cannot deliver knowledge of nonactual (metaphysical) possibilities. We are not supposed to be able to know that a proposition p is necessary or that p is possible (if p is false) by sense perception. This paper aims to establish that the role of sense perception is not so limited. It argues that we can know lots of modal facts by perception. While the most straightforward examples concern possibility and contingency, others concern (...) necessity and impossibility. The possibility of a perceptual route to some modal knowledge is not as radical as it may at first sound. On the contrary, acknowledging it has benefits. (shrink)

Our chapter interrogates the conditions that give rise to the possibility of the Event and proposes a Lacanian-Badiouian perspective to think through conditions for the truth procedures of love and politics. First, we situate the Event, Possibility and Truth in both Badiou and Lacan, which brings forward conceptual tensions between truth and knowledge as presented in the psychoanalytic act. We propose with Badiou and Lacan that the emergence of possibility follows a logic that rupture compulsive repetition and (...) whose effect is precisely the Event which results in knowledge of a savoir faire, of transmissible quality, that grant re-inscription (a new writing of the necessary) and/or a partial inscription of the impossible. The notion of love as beyond narcissism, allows us to discuss how to reimagine politics anew, including approaching it through the problem of ecology. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:BOOK REVIEWS 503 Possibility, Necessity, and Existence: Abbagnarw and His Predecessors. By NINO LANGIULLI. Philadelphia: Temple University Press, 1992. Pp. xv + 205. $44.95 (cloth). Although Nicola Abbagnano would agree in some sense with the currently fashionable claim that metaphysics is dead, Nino Langiulli's treatment of Abbagnano's thought constitutes a challenge to that claim. The aim, of Possibility, Necessity, and Existence is "to expound and elucidate historically (...) and analytically the concepts of possibility, necessity, and existence as they are refracted through the thought of the twentieth-century Italian philosopher Nicola Abbagnano." Langiulli characterizes Abbagnano as a bold and original thinker whose defense of "possibility" as the fundamental sense of being is understood by Abbagnano himself as an anti-metaphysical position. In his critical reflections, however, especially in the last chapter, Langiulli shows that Abbagnano is indeed engaged in an inquiry that can only be called metaphysical. Parts I and II are preparatory to the third part in which the concept of possibility and its relation to existence are most directly addressed. Part I provides a historical overview of four phases of the movement of Abbagnano's thought "from a positive existentialism to a radical empiricism." Abbagnano's version of existentialism is "positive" in that it sees in human finitude the very possibility of man's relationship with being. Here Abbagnano is distinguished from other existentialists such as Heidegger, Jaspers, Marcel, and Sartre. His criticisms of these positions are among the most important and interesting parts of the book. Heidegger and Jaspers both begin by apprehending human existence as a structure of possibilities but then reduce human existence to a structure of impossibilities. Christian existentialists such as Marcel really treat possibilities as potentialities to be inevitably realized. For Sartre all possibilities are equivalent, but for Abbagnano "the complete arbitrariness of choice among human possibilities does not imply freedom at all, but the impossibility of choice" (18). Here also Langiulli's comparison of Abbagnano with Quine, Sellars, and Rorty is pertinent and illuminating: Abbagnano would share Rorty's criticism of Quine and Sellars for holding on to vestiges of the old empiricism, but Abbagnano would not accept Rorty's "emptying" of philosophy itself. The influence of Abbagnano on his student Umberto Eco and on Gianni Vattimo and the differences between Abbagnano and Derrida's views of possibility are spelled out by Langiulli. In a section entitled "Dumping Philosophy and the Madness of It That Is Also Folly," Langiulli locates Abbagnano clearly and precisely within the debate over the legitimacy of reason. Abbagnano finds the basis of philosophical madness in the persistent tendency to take one aspect of human life as an absolute determinant, thus marginalizing or ignoring all others. "This privileged status has even been attributed to reason, but only when it 504 BOOK REVIEWS is absolutized or divinized as a superhuman force regulating the whole of nature, humanity included, according to necessary and necessitating laws" (39). So, for example, the order of mathematics or the techniques of verification and control employed in physics are transferred to the human world. But Abbagnano's rejection of absolutized reason is not a rejection of reason as such. He sees the current favoring of the nonrational and irrational aspects of life as a kind of folly and madness, "the vertigo of absurdity." The deliberate and crass ignorance of history and the search for novelty are also forms of madness. Part II consists of four chapters that trace the sources for Abbagnano's concept of possibility. The first of these sources is Plato's treatment of existence and possibility in the Sophist, where Abbagnano finds what he takes to be the antecedent for his own thought and for existentialism in general: the idea that possibility is both the structure and the ground of existing things. The two persistent themes of Greek metaphysics that Abbagnano is concerned to overcome are found most explicitly in Aristotle: the priority of actuality over possibility and the primacy of necessity over possibility. Kant is credited with opening the path for contemporary thought with his concept of real possibility (as distinguished from merely logical possibility). Finally, Abbagnano is indebted to Kierkegaard's criticisms of Aristotle and Hegel in the Philosophical... (shrink)

What is possible, according to the empiricist conception, is what our evidence positively allows; and what is necessary is what it compels. These notions, along with logical possibility, are the only defensible notions of possibility and necessity. In so far as nomic and metaphysical possibilities are defensible, they fall within empirical possibility. These empirical conceptions are incompatible with traditional possible world semantics. Empirically necessary propositions cannot be defined as those true in all possible worlds. There (...) can be empirical possibilities without empirical necessities. The duality of possibility and necessity can be degenerate and can even be falsified. (shrink)

The article analyzes the possibilities and limitations of artificial intelligence. The article considers the subjectivity of artificial intelligence, determines its necessity for solving intellectual problems depending on the possibility of representing the real world as a deterministic system. Methodological limitations of artificial intelligence, which is based on the use of big data technologies, are stated. These limitations cause the impossibility of forming a holistic representation of the objects of cognition and the world as a whole. As a (...) tool for deterministic description of the universe it is proposed to use empirical-metaphysical general theory of systems, which is an extension of existing general theories of systems due to ontological justification of the phenomenon of isomorphism and definition of a limited set of laws, rules, patterns and primitives of forms and relations of objects in the universe. The distinction of natural (human) and artificial intelligence is considered, including the realization of multisystem integration of intelligence in physical, biological, social and spiritual systems. A philosophically grounded approach to ensuring the evolutionary properties of artificial intelligence is formulated, based on the inclusion of non-equilibrium mechanisms through which stability is realized. (shrink)

David Armstrong's book is a contribution to the philosophical discussion about possible worlds. Taking Wittgenstein's Tractatus as his point of departure, Professor Armstrong argues that nonactual possibilities and possible worlds are recombinations of actually existing elements, and as such are useful fictions. There is an extended criticism of the alternative-possible-worlds approach championed by the American philosopher David Lewis. This major work will be read with interest by a wide range of philosophers.

Information is often modelled as a set of relevant possibilities, treated as logically possible worlds. However, this has the unintuitive consequence that the logical consequences of an agent's information cannot be informative for that agent. There are many scenarios in which such consequences are clearly informative for the agent in question. Attempts to weaken the logic underlying each possible world are misguided. Instead, I provide a genuinely psychological notion of epistemic possibility and show how it can be (...) captured in a formal model, which I call a fan. I then show how to use fans to build formal models of being informed, as well as knowledge, belief and information update. (shrink)

There are two ways interpreters have tended to understand the nature of the laws of Kant’s pure general logic. On the first, these laws are unconditional norms for how we ought to think, and will govern anything that counts as thinking. On the second, these laws are formal criteria for being a thought, and violating them makes a putative thought not a thought. These traditions are in tension, in so far as the first depends on the possibility of thoughts (...) that violate these laws, and the second makes violation impossible. In this essay I develop an interpretation of Kant’s pure general logic that overcomes this tension. It accounts for the possibility of logical mistakes, as the first tradition does, while still establishing the absolute impossibility of logical aliens, as the second tradition does. I then argue that the formalist insight that illogical exercises of the understanding are not alternative ways coherent thoughts could have been, but are mere confusions, is fundamental for achieving a proper understanding of the absolute normativity of the laws of pure general logic. (shrink)

The core idea of the ontological proof is to show that the concept of existence is somehow contained in the concept of God, and that therefore God’s existence can be logically derived—without any further assumptions about the external world—from the very idea, or definition, of God. Now, G.W. Leibniz has argued repeatedly that the traditional versions of the ontological proof are not fully conclusive, because they rest on the tacit assumption that the concept of God is possible, i.e. free from (...) contradiction. A complete proof will rather have to consist of two parts. First, a proof of premiseGod is possible. Second, a demonstration of the “remarkable proposition”If God is possible, then God exists. The present contribution investigates an interesting paper in which Leibniz tries to prove proposition. It will be argued that the underlying idea of God as a necessary being has to be interpreted with the help of a distinguished predicate letter ‘E’ as follows:\\). Proposition which Leibniz considered as “the best fruit of the entire logic” can then be formalized as follows:\) \rightarrow \, E)\). At first sight, Leibniz’s proof appears to be formally correct; but a closer examination reveals an ambiguity in his use of the modal notions. According to, the possibility of the necessary being has to be understood in the sense of something which possibly exists. However, in other places of his proof, Leibniz interprets the assumption that the necessary being is impossible in the diverging sense of something which involves a contradiction. Furthermore, Leibniz believes that an »impossible thing«, y, is such that contradictory propositions like \\) and \\) might both be true of y. It will be argued that the latter assumption is incompatible with Leibniz’s general views about logic and that the crucial proof is better reinterpreted as dealing with the necessity, possibility, and impossibility of concepts rather than of objects. In this case, the counterpart of turns out to be a theorem of Leibniz’s second order logic of concepts; but in order to obtain a full demonstration of the existence of God, the counterpart of, i.e. the self-consistency of the concept of a necessary being, remains to be proven. (shrink)

A neo-Kantian debate within analytic philosophy, in our reading, would evaluate thevalue of the following question: how the codification of the elements of a representation creates spaces of identification to theorize the possibilities oftruth, in two fields, the analytical and in the synthetic? In the analytic, the theory involves theability to conceptually interpret relations of possibility and impossibility; in the synthetic, thetheory involves the extra-conceptual supplementation of the alignment with the verifiers,providing a measure to encode the semantic (...) contribution of both experience simpliciter andexperience with concepts, made by schemas, analogical systems, etc. We suggest revitalizingthe theory of a priori syntheses, dialoguing with Kantian aspects of Husserl’s SixthInvestigation and confronting the orthodox semantics of empiricist inspiration.Although, in large part, a theory of judgments is equivalent to a dynamic production of models,simplifications and analogies, the focus on the production of synthetic and a priori judgmentspresents some independent problems, which, in our reading, would enrich the universe ofanalytic philosophy and would facilitate the reading of the development of the pragmatic shiftphase, which took place in the second half of the 20th century.Keywords: synthesis a priori; semantics; pragmatism. (shrink)

Zwart and Franssen’s impossibility theorem reveals a conflict between the possible-world-based content-definition and the possible-world-based likeness-definition of verisimilitude. In Sect. 2 we show that the possible-world-based content-definition violates four basic intuitions of Popper’s consequence-based content-account to verisimilitude, and therefore cannot be said to be in the spirit of Popper’s account, although this is the opinion of some prominent authors. In Sect. 3 we argue that in consequence-accounts, content-aspects and likeness-aspects of verisimilitude are not in conflict with each other, but (...) in agreement. We explain this fact by pointing towards the deep difference between possible-world- and the consequence-accounts, which does not lie in the difference between syntactic versus semantic formulations, but in the difference between ‘disjunction-of-possible-worlds’ versus ‘conjunction-of-parts’ representations of theories. Drawing on earlier work, we explain in Sect. 4 how the shortcomings of Popper’s original definition can be repaired by what we call the relevant element approach. We propose a quantitative likeness-definition of verisimilitude based on relevant elements which provably agrees with the qualitative relevant content-definition of verisimilitude on all pairs of comparable theories. We conclude the paper with a plea for consequence-accounts and a brief analysis of the problem of language-dependence. (shrink)

Islamic theological contradictions are metaphysical contradictions as opposed to logical and semantic ones. I shall demonstrate that if these theological contradictions are tolerable on the theoretical account of metaphysical dialetheism, then logical space, despite being the space of all possibilities, does not accommodate them in virtue of Chalmers’s ‘deep epistemic possibility’. To resolve this issue, I offer a recalibration of the modal concept of possibility. Doing so would redraw a demarcation between what is possible and (...) what is not. Consequently, we can expand logical space, so it is properly inclusive of all possibilities, including metaphysical dialetheism. Expanding logical space in this way would repudiate Chalmers’s ‘deep epistemic possibility’ and make room for Islamic theological contradictions. (shrink)

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

This work explains how human beings can live more peacefully with one another by understanding the conditions of possibility for dialogue. Philosophically, this challenge is articulated as the problem of: how dialogue as dia-logos is possible when the shared logos is precisely that which is in question. Emmanuel Levinas, in demonstrating that the shared logos is a function of interhuman relationship, helps us to make some progress in understanding the possibilities for dialogue in this situation. If the terms (...) of the argument to this point are taken largely from Levinas's 1961 Totality and Infinity, Dudiak further proposes that Levinas's 1974 Otherwise than Being can be read as a deepening of these earlier analyses, delineating, both the conditions of possibility and impossibility for discourse itself. Throughout these analyses Dudiak discovers that in Levinas's view dialogue is ultimately possible, only for a gracious subjectivity already graced by God by way of the other, but where the word God is inseparable from my subjectivity as graciousness to the other. Finally, for Levinas, the facilitation of dialogue, the facilitation of peace, comes down to the subject's capacity and willingness to be who he or she is, to take the beautiful risk of a peaceful gesture offered to the other, and that peace, in this gesture itself. As Levinas himself puts it: "Peace then is under my responsibility. I am a hostage, for I am alone to wage it, running a fine risk, dangerously." Levinas's philosophical discourse is precisely itself to be read as such a gesture. (shrink)

We present a theory of truth in fiction that improves on Lewis's [1978] ‘Analysis 2’ in two ways. First, we expand Lewis's possible worlds apparatus by adding non-normal or impossible worlds. Second, we model truth in fiction as belief revision via ideas from dynamic epistemic logic. We explain the major objections raised against Lewis's original view and show that our theory overcomes them.

Can the humanities survive in an age of science? Yes, if analytic philosophers will only stop picking on traditional philosophy and recognize the latter's proper and legitimate role in society. That role according to Veatch, is one that enables man to grasp the nontechnical meaning of our everyday world where we learn to know and understand the nature of things. Such knowledge serves as the necessary ground for not only our common sense attitudes, but also for establishing values and norms (...) for a moral life. What is more, Veatch contends, this knowledge of man, his nature, and his values is not merely emotive or psychological; rather, it is factual. Using traditional logic as its organon, knowledge of a more humanistic variety can establish itself as factual in spite of analytical claims to the contrary. Thus Veatch proceeds from the general problem of the humanities versus science to the more specific area of the two logics: traditional Aristotelian logic and modern symbolic logic. The former is the proper tool of the humanities, the latter serves the method of the physical sciences. Both logics deal with facts in their respective areas. Traditional logic lays bare the facts that make human life meaningful, while symbolic logic operates with formal structures that make technological progression possible. One logic does not cancel out the other. Veatch prefers to view the two logics as a "both... and" structure rather than as an "either... or" situation. To effect this he launches a counterattack against analytic philosophy's repudiation of traditional logic. He charges certain analysts with committing a fallacy that makes necessities and impossibilities a mere function of our language rules. Veatch, however, sees our rules of language as determined by real necessities in the world. He claims that Wittgenstein's celebrated attack on the doctrine of essences never really denies Aristotle's notion of substance as the formal or intelligible aspect of individual entities. Although his justification of traditional logic as a grammar for discourse in the humanities presupposes certain metaphysical commitments, on the whole his plea for traditional philosophy is persuasive.--J. J. R. (shrink)

A través de los recursos esenciales de la semantica de los mundos posibles se comparan y relacionan, por un lado, la dimensión científica y filosófica, y por otro, la dimensión tecnica y la utópica, utilizándose para ello las relaciones entre composibilidad (o compatibilidad) y existencia, y entre el mundo actual, en el que opera la técnica, y mundos posibles, hacia los que se proyecta la utopía. En esta tarea resulta de interés prestar atención a la problematica clasica acerca de los (...) poliedros posibles e imposibles, en relación con el problema de la afectación, exclusión o ajuste de los “monstruos” de la lógica o de la razón.Through the essential means of the semantics of possible worlds, some dimensions are compared and related: firstly, the scientific and philosophical dimension, and secondly the technical and utopian dimension. For that purpose the relationship between compossibility (or compatibility) and existence are used as well as that between the real world, in which technique works, and possible worlds, towards utopia is oriented. In this task it is interesting to pay attention to the classic issue of possible and impossible polyhedrons, concerning affectation, exclusion or fitting of “monsters” of logic or of reason. (shrink)

In this article, I intend to show what the metaphysical possibility is, distinguishing it from the logical and the physical possibilities, and then to indicate that at least there is two kinds of metaphysical possibilities, i.e., the potentialities of the things and the possibilities of the events to occur. This is an important goal because it makes clearer the discussion about possibilities. To show what the metaphysical possibility is, I try to show that (...) we need an absolute modality for the debate about what is possible do not be trivial. And to indicate that there are two kinds of metaphysical possibilities, I show that we can talk independently about these two notions of possibility, and that the debate between determinism and indeterminism presupposes such distinction. The conclusion we achieve is that there really are these two kinds of metaphysical possibilities, and that if we don’t want to be ambiguous, we have good reasons to use such distinction in our theories about the possibilities. (shrink)

Any worlds semantics for intentionality has to provide a plenitudinous theory of impossibility: For any impossible proposition, it should provide a world where it is true. Hence, also any semantics for impossibility statements that extends Lewis’s concretism about possible worlds should be plenitudinous. However, several such proposals for impossibilist semantics fail to accommodate two kinds of impossibility that, albeit not unheard of, have been largely neglected in the literature on impossible worlds, but that are bound to arise (...) in the Lewisian context. The proposals discussed here stop short of plenitude because they adhere to what Lewis occasionally referred to as ‘ontological truth’, as they lack the semantic ability to misrepresent ontological facts. The paper develops a framework for systematic misrepresentations on the basis of Mares’s situation-based account of impossible ‘worlds’, and which confines ‘ontological truth’ to possibility. It thus illustrates how a plenitude of impossibilities can be achieved. (shrink)

That the question of identity takes on a sense of urgency, one with its own possibilities and impossibilities, the moment that identity is bound up with death, is hardy surprising. What follows are a series of reflections on the question of identity, Jewish identity, raised by Jean Améry’s remarkable text On the Necessity and Impossibility of Being a Jew. Améry’s text was of course published in the wake of his own experiences as an active member of the (...) resistance, as having been imprisoned in Auschwitz and as the victim of torture. Philosophically, rather than biographically, if there were a point of comparison, then it is to Levinas’s 1947 text Etre juif. Both pose the problem of how the question of Jewish identity, Jewish being, is to be understood in the wake of the Shoah. The meaning of the formulations - Jude zu sein, Jude sein, Etre juif, Jewish being – delimits the question to be addressed. This will be the case even if its point of address, namely what the question stages, is itself far from straightforward. Moreover, while what is demanded within that question is itself philosophically important, it is equally the case that the question of Jewish being is at work within both communities and synagogues across the Jewish world. As a consequence it is as much a philosophical question as it is one that has a structuring effect on how Jewish survival is conceived. How survival is understood is an issue that continues to exert its force. Who is the subject of survival? What is the subject of survival? Who or what has been subjected to the issue of survival? Survival is both more nuanced and complex than the brute fact of an afterlife. Jewish being as a present question – a question of the present - continues therefore. (shrink)

Some relations between physics and finitary and infinitary mathematics are explored in the context of a many-minds interpretation of quantum theory. The analogy between mathematical ``existence'' and physical ``existence'' is considered from the point of view of philosophical idealism. Some of the ways in which infinitary mathematics arises in modern mathematical physics are discussed. Empirical science has led to the mathematics of quantum theory. This in turn can be taken to suggest a picture of reality involving possible minds and the (...) physical laws which determine their probabilities. In this picture, finitary and infinitary mathematics play separate roles. It is argued that mind, language, and finitary mathematics have similar prerequisites, in that each depends on the possibility of possibilities. The infinite, on the other hand, can be described but never experienced, and yet it seems that sets of possibilities and the physical laws which define their probabilities can be described most simply in terms of infinitary mathematics. (shrink)

In this paper, I explore the possibility of applying the methods and results of Judgement Aggregation to the problem of logical disagreement. I develop and evaluate different ways in which individuals who logically disagree can generate a collective logic. I prove a version of the discursive paradox, where the majority voting of a group of structural logicians can give rise to a substructural logic; then I develop a more general impossibility result. After this, I analyze different ways (...) to avoid the paradox, in particular some methods which appeal to domain restrictions. Finally, I consider the application of these results to the discussion on semantic paradoxes. (shrink)

This book defends a radical new theory of contingency as a physical phenomenon. Drawing on the many-worlds approach to quantum theory and cutting-edge metaphysics and philosophy of science, it argues that quantum theories are best understood as telling us about the space of genuine possibilities, rather than as telling us solely about actuality. When quantum physics is taken seriously in the way first proposed by Hugh Everett III, it provides the resources for a new systematic metaphysical framework encompassing (...) class='Hi'>possibility, necessity, actuality, chance, counterfactuals, and a host of related modal notions. -/- Rationalist metaphysicians argue that the metaphysics of modality is strictly prior to any scientific investigation; metaphysics establishes which worlds are possible, and physics merely checks which of these worlds is actual. Naturalistic metaphysicians respond that science may discover new possibilities and new impossibilities. This book's quantum theory of contingency takes naturalistic metaphysics one step further, allowing that science may discover what it is to be possible. As electromagnetism revealed the nature of light, as acoustics revealed the nature of sound, as statistical mechanics revealed the nature of heat, so quantum physics reveals the nature of contingency. (shrink)

I think that virtually all contemporary theists, agnostics and atheists believe this is logically possible. Indeed, the main philosophical tradition from Plato to the present has assumed that the sentence, "God is the originating cause of the universe", does not express a logical contradiction, even though many philosophers have argued that this sentence either is synthetic and meaningless (e.g., the logical positivists) or states a synthetic and a priori falsehood (e.g., Kant and Moore), or states a synthetic and (...) a posteriori falsehood (e.g., contemporary defenders of the probabilistic argument from evil). (shrink)

It is notoriously difficult to find an intuitively satisfactory rule for evaluating populations based on the welfare of the people in them. Standard examples, like total utilitarianism, either entail the Repugnant Conclusion or in some other way contradict common intuitions about the relative value of populations. Several philosophers have presented formal arguments that seem to show that this happens of necessity: our core intuitions stand in contradiction. This paper assesses the state of play, focusing on the most powerful of these (...) ‘impossibility theorems’, as developed by Gustaf Arrhenius. I highlight two ways in which these theorems fall short of their goal: some appeal to a supposedly egalitarian condition which, however, does not properly reflect egalitarian intuitions; the others rely on a background assumption about the structure of welfare which cannot be taken for granted. Nonetheless, the theorems remain important: they give insight into the difficulty, if not perhaps the impossibility, of constructing a satisfactory population axiology. We should aim for reflective equilibrium between intuitions and more theoretical considerations. I conclude by highlighting one possible ingredient in this equilibrium, which, I argue, leaves open a still wider range of acceptable theories: the possibility of vague or otherwise indeterminate value relations. (shrink)

I examine issues in the philosophy of religion at the intersection of what possibilities there are and what a God, as classically conceived in the theistic philosophical tradition, would be able to do. The discussion is centered around arguing for an incompatibility between theism and two principles about possibility and ability, and exploring what theists should say about these incompatibilities. -/- I argue that theism entails that certain kinds and amounts of evil are impossible. This puts theism in (...) conflict with popular principles of modal recombination. However, theists have plausible explanations for the violations of recombination that they posit, and can suitably amend these principles without giving up their usefulness in accounting for what possibilities there are. -/- I also argue that despite the impossibility of these evils, God is able to bring these evils about. This puts theism in conflict with the principle that no one is able to do the impossible. However, theists can give a plausible account of why God is unique in being able to do the impossible, and have distinctive resources to address the arguments in favor of the idea that no one is able to do the impossible. And by denying this principle, theists are able to resolve several otherwise difficult puzzles, including reconciling conflicts between the divine attributes. (shrink)