Computational complexity is a discipline of computer science and mathematics which classifies computational problems depending on their inherent difficulty, i.e. categorizes algorithms according to their performance, and relates these classes to each other. P problems are a class of computational problems that can be solved in polynomial time using a deterministic Turing machine while solutions to NP problems can be verified in polynomial time, but we still do not know whether they can be solved in polynomial time as well. A (...) solution for the so-called NP-complete problems will also be a solution for any other such problems. Its artificial-intelligence analogue is the class of AI-complete problems, for which a complete mathematical formalization still does not exist. In this chapter we will focus on analysing computational classes to better understand possible formalizations of AI-complete problems, and to see whether a universal algorithm, such as a Turing test, could exist for all AI-complete problems. In order to better observe how modern computer science tries to deal with computational complexity issues, we present several different deep-learning strategies involving optimization methods to see that the inability to exactly solve a problem from a higher order computational class does not mean there is not a satisfactory solution using state-of-the-art machine-learning techniques. Such methods are compared to philosophical issues and psychological research regarding human abilities of solving analogous NP-complete problems, to fortify the claim that we do not need to have an exact and correct way of solving AI-complete problems to nevertheless possibly achieve the notion of strong AI. (shrink)

The purpose of this essay is to shed some light on a certain type of sentence, which I call a borderline contradiction. A borderline contradiction is a sentence of the form F a ∧ ¬F a, for some vague predicate F and some borderline case a of F , or a sentence equivalent to such a sentence. For example, if Jackie is a borderline case of ‘rich’, then ‘Jackie is rich and Jackie isn’t rich’ is a borderline contradiction. Many theories (...) of vague language have entailments about borderline contradictions; correctly describing the behavior of borderline contradictions is one of the many tasks facing anyone offering a theory of vague language. Here, I first briefly review claims made by various theorists about these borderline contradictions, attempting to draw out some predictions about the behavior of ordinary speakers. Second, I present an experiment intended to gather relevant data about the behavior of ordinary speakers. Finally, I discuss the experimental results in light of several different theories of vagueness, to see what explanations are available. My conclusions are necessarily tentative; I do not attempt to use the present experiment to demonstrate that any single theory is incontrovertibly true. Rather, I try to sketch the auxiliary hypotheses that would need to be conjoined to several extant theories of vague language to predict the present result, and offer some considerations regarding the plausibility of these various hypotheses. In the end, I conclude that two of the theories I consider are better-positioned to account for the observed data than are the others. But the field of logically-informed research on people’s actual responses to vague predicates is young; surely as more data come in we will learn a great deal more about which (if any) of these theories best accounts for the behavior of ordinary speakers. (shrink)

Are moral terms semantically plastic—that is, would very slight changes in our patterns of use have shifted their meanings? This is a delicate question for moral realists. A 'yes' answer seems to conflict with the sorts of intuitions that support realism; but a 'no' answer seems to require a semantics that involves hefty metaphysical commitments. This tension can be illustrated by thinking about how standard accounts of vagueness can be applied to the case of moral terms, and also by considering (...) how realists should respond to the Moral Twin Earth problem. After presenting the puzzle, I will argue that moral realists can accept the semantic plasticity of moral expressions while accounting for contrary intuitions in a way that is nearly cost-free. (shrink)

I investigate the consequences for semantics, and in particular for the semantics of tense, if time is assumed to have a branching structure not out of metaphysical necessity (to solve some philosophical problem) but just as a contingent physical fact, as is suggested by a currently-popular approach to the interpretation of quantum mechanics.

The extensions of vague predicates like ‘is bald’, ‘is tall’, and ‘is a heap’ apparently lack sharp boundaries, and this makes such predicates susceptible to soritical reasoning, i.e. reasoning that leads to some version of the notorious sorites paradox. This essay is concerned with a certain kind of theory of vagueness, according to which the symptoms and puzzles of vagueness should be accounted for in terms of a particular species of context sensitivity exhibited by vague expressions. The basic idea is (...) that the extensions of vague predicates vary with certain contextual factors, and that this fact can explain why they appear to lack sharp boundaries. This kind of view is referred to as contextualism about vagueness. A detailed characterisation of contextualism about vagueness is given in chapter two and three. In chapter two, a generic version of contextualism about vagueness is developed, and some alternative forms of context sensitivity are introduced. In chapter three, the specific contextual factors appealed to by different contextualists are discussed. In chapter four, different contextualist diagnoses of the sorites paradox are considered, and found to be problematic in various ways. It is argued that contrary to what some of its proponents have claimed, contextualism about vagueness is not superior to other comparable theories of vagueness when it comes to explaining the appeal of soritical reasoning. In chapter five, a certain version of the sorites paradox, known as the forced march sorites, is discussed. It is argued that “data” about how speakers would behave in the forced march cannot lend any firm support to contextualism about vagueness. In chapter six, some problems concerning the instability of the contextual factors are considered. One problem is that contextualist diagnoses of the sorites which locate a fallacy of equivocation in the reasoning seem to render non-soritical reasoning fallacious as well. A model for treating this problem is suggested, but on closer consideration, it turns out to be problematic. Moreover, this model is of no help in solving the more general problem that even if classical logic remains valid for vague language on some contextualist views, the instability of the extensions of vague predicates makes it difficult to know when a certain piece of reasoning instantiates a valid argument form. Other difficulties arise with respect to speech reports and belief contents. Chapter seven concludes with a summary and some methodological remarks. (shrink)

This is an encyclopedia entry on vagueness, focusing mainly on the opposition between re re and de dicta (linguistic or cognitive) accounts.

It has been argued that quantum mechanics forces us to accept the existence of metaphysical, mind-independent indeterminacy. In this paper we provide an interpretation of the indeterminacy involved in the quantum phenomena in terms of a view that we call Plural Metaphysical Supervaluationism. According to it, quantum indeterminacy is captured in terms of an irreducibly plural relation between the actual world and various misrepresentations of it.

My starting point is that discussions in philosophy about the ontology of technical artifacts ought to be informed by classificatory practices in engineering. Hence, the heuristic value of the natural-artificial distinction in engineering counts against arguments which favour abandoning the distinction in metaphysics. In this chapter, I present the philosophical equipment needed to analyse classificatory practices and then present a case study of engineering practice using these theoretical tools. More in particular, I make use of the Collectivist Account of Technical (...) Artifacts (CAT) according to which there are different classificatory practices for natural, artificial, and social objects. I demonstrate that in the community studied, artificial kinds are marked by distinctive classificatory practices. The presence of these distinctive classificatory practices in engineering with regard to artificial kinds should inform discussions about the ontology of technical artifacts just as the distinctive classificatory practices in natural science inform discussions about natural kinds. (shrink)

In a recent paper, Lee Kerckhove and Sara Waller (hereafter K & W) argue that the concept of personhood is irrelevant for the abortion debate.1 Surprisingly, this irrelevance is due merely to the fact that the predicate ‘being a person’ — hereafter ‘personhood’ — is inherently vague. This vagueness, they argue, reduces ‘personhood’ to incoherency and disqualifies the notion from being a useful moral concept. In other words, if ‘personhood’ isn’t a precise notion with well-defined boundaries, then it cannot be (...) of any use in the debate over the permissibility of abortion. This argument is mistaken. While it may be true that ‘personhood’ is irrelevant for the debate over abortion (a substantive issue not dealt with in this paper), it is not true that ‘personhood’ should be disqualified merely because it is vague. Section 2 of the paper is a quick survey in which I briefly review the importance of ‘personhood’ in some of the more recent literature concerning the moral status of abortion. Section 3 is a reconstruction of K & W’s argument against the relevancy of ‘personhood’ and a criticism showing why their argument fails. Section 4 approaches the use of a vague predicate in moral debate and explores the application of ‘personhood’ given three contemporary solutions to vagueness: degree theory, epistemicism and supervaluationism. (shrink)

Few views are as widely held as the Standard View of Identity. Here I am concerned with minority views that depart from the standard account. First, I attempt to illuminate such views and the debates concerning them by identifying the principles of identity at issue, articulating some of the assumptions underlying the debates, and presenting some of the evidence used against the Standard View of Identity. Second, I enter two of these debates myself. I first defend two Non-Standard Views of (...) Identity from the charge that they violate a principle of identity, namely the Transitivity of Identity. I then present an overlooked consequence of another Non-Standard View of Identity that challenges the view on one of its own methodological principles. Third, I draw on recent work in ontological and parthood pluralism to show how one might be led to think that there is more than one way of being identical. That is, I show how one might be an identity pluralist. (shrink)

Time passes, and the inexorability of its passing has deep emotional significance. One of the main themes of this thesis involves an investigation into the metaphysical nature of the passage of time. What sort of metaphysical account of passage should be given? And do our emotional responses to temporal passage have metaphysical implications? The other main theme of the thesis is the issue of the metaphysics of persistence. When a thing is present at more than one time, what is the (...) metaphysical underpinning of its persistence? Some subsidiary issues, which are nevertheless important in their own right, are also discussed. There are interesting connections between the issues of persistence and these further issues, which include the nature of vagueness, and the distinction between intrinsic and extrinsic properties. (shrink)

In this paper, I argue that the disjunction elimination rule presupposes the principle that a true disjunction contains at least one true disjunct. However, in some contexts such as supervaluationism or quantum logic, we have good reasons to reject this principle. Hence, disjunction elimination is restricted in at least one respect: it is not applicable to disjunctions for which this principle does not hold. The insight that disjunction elimination presupposes the principle that a true disjunction contains at least one true (...) disjunct is applied to two arguments which argue for this very principle. I show that these arguments are rule-circular since they rest on disjunction elimination. I claim that rule-circularity better explains why the arguments fail than the explanations provided by Rumfitt (2015), which, for instance, rely on controversial principles about truth. (shrink)

In a paper called 'Definiteness and Knowability', Tim Williamson addresses the question whether one must accept that vagueness is an epistemic phenomenon if one adopts classical logic and a disquotational principle for truth. Some have suggested that one must not, hence that classical logic and the disquotational principle may be preserved without endorsing epistemicism. Williamson’s paper, however, finds ‘no plausible way of substantiating that possibility’. Its moral is that ‘either classical logic fails, or the disquotational principle does, or vagueness is (...) an epistemic phenomenon’. The moral of this paper, on the contrary, is that there is a plausible way of substantiating that possibility. The option it contemplates looks like a view that Williamson dismisses at the beginning of his paper, and that others regard as unworthy of serious consideration. (shrink)

This paper focuses on two interrelated issues about the prospects for research projects in experimental philosophical logic. The first issue is about the role that logic plays in such projects; the second involves the role that experimental results from the cognitive sciences play in them. I argue that some notion of logic plays a crucial role in these research projects, and, in turn, the results of these projects might inform substantive debates in the philosophy of logic.

Nature is complex, exceedingly so. A repercussion of this “complex world constraint” is that it is, in practice, impossible to connect words to the world in a foolproof manner. In this paper I explore the ways in which the complex world constraint makes vagueness, or more generally imprecision, in language in practice unavoidable, illuminates what vagueness comes to, and guides us to a sensible way of thinking about truth. Along the way we see that the problem of ceteris paribus laws (...) is exactly the problem of vagueness and susceptible to similar treatment. (shrink)

In order to understand consciousness one would benefit from developing a more eclectic intellectual style. Consciousness is, as proposed by almost everyone except the stubborn reductionists, a truly mysterious concept. Its study and dissection merits a multidisciplinary approach. Waving this multidisciplinary flag has positively enlarged the discussion and neurologists, psychiatrists, mathematicians, and so on, have moved to the philosophy of mind arena, first with caution and now with a more powerful voice. Identifying what we mean by consciousness is a first (...) step even when we want to deny its existence. The link between consciousness and some other mental activity is a logical next step and there is abundant literature doing this, but not all of them differentiate among associated yet different phenomena. (shrink)

Decisions are made under uncertainty when there are distinct outcomes of a given action, and one is uncertain to which the act will lead. Decisions are made under indeterminacy when there are distinct outcomes of a given action, and it is indeterminate to which the act will lead. This paper develops a theory of (synchronic and diachronic) decision-making under indeterminacy that portrays the rational response to such situations as inconstant. Rational agents have to capriciously and randomly choose how to resolve (...) the indeterminacy relevant to a given choice-situation, but such capricious choices once made constrain how they will choose in the future. The account is illustrated by the case of self-interested action in situations where it is indeterminate whether you yourself will survive to benefit or suffer the consequences. The conclusion emphasizes some distinctive anti-hedging predictions of the account. (shrink)

This is an old draft of a paper that seeks to find the minimum cognitive/practical role for indeterminacy that we get if we assume a fully classical logic and semantics, but reject epistemicism. The ambition is to connect that classical setting to the framework for rational belief and decision I described in "Decision Making under Indeterminacy".

I explore the thesis that the future is open, in the sense that future contingents are neither true nor false. The paper is divided into three sections. In the first, I survey how the thesis arises on a variety of contemporary views on the metaphysics of time. In the second, I explore the consequences for rational belief of the ‘Aristotelian’ view that indeterminacy is characterized by truth-value gaps. In the third, I outline one line of defence for the Aristotelian against (...) the puzzles this induces: treating opinion about future contingents as a matter of fictional belief rather than simple belief. (shrink)

Most words in natural language are vague, that is to say, they lack sharp boundaries and, hence, they have (actual or potential) borderline cases, where the word in question neither definitely applies nor definitely fails to apply. Vagueness gives rise to paradoxes, the best known of which is the sorites (concerned with how many grains of sand are needed to make a heap). Besides offering a solution to such paradoxes, a theory of vagueness should systematically describe how the truth conditions (...) of sentences with vague terms are determined; and it should also define the right logical principles for reasoning with such sentences. This article offers an introduction to the main theories of vagueness and to the problems they have to face. (shrink)

Three recent books have argued that Keynes’s philosophy, like Wittgenstein’s, underwent a radical foundational shift. It is argued that Keynes, like Wittgenstein, moved from an atomic Cartesian individualism to a more conventionalist, intersubjective philosophy. It is sometimes argued this was caused by Wittgenstein’s concurrent conversion. Further, it is argued that recognising this shift is important for understanding Keynes’s later economics. In this paper I argue that the evidence adduced for these theses is insubstantial, and other available evidence contradicts their claims.

What are we? Despite much discussion in historical and contemporary philosophy, we have not yet settled on an answer. A satisfactory personal ontology, an account of our metaphysical nature, will be informed by issues in the metaphysics of material objects. In the dissertation, I target two prominent materialist ontologies: animalism, the view that we are numerically identical to human organisms, and constitutionalism, the view that we are constituted by, but not identical to, human organisms. Because of the problems that arise (...) from endorsing these ontologies, I instead advance immaterialism, the view that we are essentially immaterial. In Chapter 2, I discuss how animalists must respond to a widely-discussed metaphysical puzzle, the problem of the many. This puzzle prompts some to endorse revisionary ontologies of material objects, and I argue that the animalist cannot appeal to these revisionary ontologies to solve the puzzle as it arises for personal ontology. In addition, solutions that don’t involve a commitment to revisionary ontology will be unavailable to the animalist: I argue that if animalists make use of non-revisionary solutions to the problem, they must abandon the most successful argument for their view. Absent their most successful argument, animalists will need to motivate the view in some other way. Some new arguments for animalism have been proposed, and I argue that they fail to give us reason to endorse animalism over competing ontologies. Without a strong argument, we should not prefer animalism over the other, more attractive, views. In Chapter 3, I show how constitutionalists face a different problem: explaining how the person is not the very same thing as the human organism, despite sharing the very same parts and occupying the very same physical space. We think that the person and the organism are different things because they have different modal profiles – the human organism can survive permanent loss of psychological life, but the person, presumably, cannot. Constitutionalists must then explain what grounds the difference in modal profiles, but such an explanation is hard to come by. This is an instance of the grounding problem, which is notoriously intractable. While the grounding problem is a well-known challenge to constitutional accounts of objects, I demonstrate that this puzzle is even more threatening when applied to persons. Some “solutions” to the problem fail to solve it at all, and solutions that might get the right result for ordinary objects require accepting that there are a multitude of persons where we ordinarily take there to be only one. We should not accept a personal ontology that requires a commitment to that multitude. I argue that the threat of the grounding problem is so great that we must reject the constitutionalist personal ontology. We will see from these puzzles in personal ontology that materialist solutions are either unsuccessful or yield unacceptable consequences. This should prompt us toward considering, instead, immaterialism. According to immaterialism, persons are not material objects, and the immaterialist can then provide solutions to the puzzles that threatened materialist ontologies. In Chapter 4, I outline these immaterialist solutions and show that the puzzles cannot be reinstantiated successfully against the immaterialist. I then discuss different available varieties of immaterialism and argue in defense of my preferred version. Ultimately, I argue that we are simple, immaterial entities that come into existence at the proper functioning of the brain. Endorsing this view of personal ontology permits us to adequately respond to metaphysical puzzles and retain judgments about persons that should be most important to us. In particular, the immaterialist has the resources to avoid the problem of too many thinkers and retain the judgment that there is exactly one person in circumstances where we take there to be just one. The immaterialist also has the resources to plausibly analyze thought experiments, such as cerebrum-swap cases, that threaten materialist ontologies. All things considered, it remains to be seen which personal ontology has the most evidence in its favor. In the context of debates that arise from material object metaphysics, however, evidence weighs in favor of immaterialism. Materialist personal ontologies are saddled with unacceptable responses to metaphysical puzzles, and endorsing materialism about persons requires taking on a very high cost: Either there are far more of us than we ordinarily take there to be, or there are no persons – far fewer of us than we ordinarily take there to be. Some might argue that these are the only acceptable options, so cost be damned. But we cannot afford to be so cavalier about our personal ontology. Instead, I advance immaterialist solutions to puzzles in personal ontology and propose that, in the interest of saving ourselves and everyone we love, we should seriously consider accounts according to which we are immaterial entities. (shrink)

Our ascriptions of content to utterances in the past attribute to them a level of determinacy that extends beyond what could supervene upon the usage up to the time of those utterances. If one accepts the truth of such ascriptions, one can either (1) argue that subsequent use must be added to the supervenience base that determines the meaning of a term at a time, or (2) argue that such cases show that meaning does not supervene upon use at all. (...) The following will argue against authors such as Lance, Hawthorn and Ebbs that first of these options is the more promising of the two. However, maintaining the supervenience thesis ultimately requires understanding the relation between use and meaning as 'normative' in two important ways. The first (more familiar) way is that the function from use to meaning must be of a sort that allows us to maintain a robust distinction between correct usage and actual usage. This first type of normativity is accepted by defenders of many more temporally restricted versions of the supervenience thesis, but the second sort of normativity is unique to theories that extend the supervenience base into the future. In particular, if meaning is partially a function of future use, we can understand other commitments we are often taken to have about meaning, particularly the commitment to meaning being 'determinate', as practical commitments that structure our linguistic practices rather than theoretical commitment that merely describe such practices. (shrink)

This paper considers a now familiar argument that the ubiquity of context -dependence threatens the project of natural language semantics, at least as that project has usually been conceived: as concerning itself with `what is said' by an utterance of a given sentence. I argue in response that the `anti-semantic' argument equivocates at a crucial point and, therefore, that we need not choose between semantic minimalism, truth-conditional pragmatism, and the like. Rather, we must abandon the idea, familiar from Kaplan and (...) others, that utterances express propositions `relative to contexts' and replace it with the Strawonian idea that speakers express propositions by making utterances in contexts. The argument for this claim consists in a detailed investigation of the particular case of demonstratives, which I argue demand such a Strawsonian treatment. I then respond to several objections, the most important of which allege that the Strawsonian account somehow undermines the project of natural language semantics, or threatens the semantics -pragmatics distinction. Please note that the paper posted here is an extended version of what was published. (shrink)

Contextualism about vagueness (hereafter ‘Contextualism’) is the view that vagueness consists in a particular species of context-sensitivity and that properly accommodating this fact into our semantic theory will yield a plausible solution to the sorites paradox.[1],[2] But Contextualism, as many commentators have noted, faces the following immediate objection: if we hold the context fixed, vagueness still remains, therefore vagueness is not a species of context-sensitivity. Call this ‘the simple objection’.[3] Absent a convincing reply to the simple objection, Contextualism is in (...) very bad shape. Oddly enough, defenders of Contextualism have said very little in reply. Proponents of the objection have tended to assume that this is because no reply is in the offing—the simple objection is taken to be unassailable. In this short paper, we sketch two replies to the simple objection which result in two very different kinds of Contextualism: Epistemicist Contextualism and Radical Contextualism. With these two theories in hand, the simple objection loses its force. (shrink)

Another paper exploring the relation between Temporal externalism and Epistemicism about Vagueness, but with slightly more emphasis on the role of constitutive norms relating to our concept of truth.

This thesis comprises three main chapters—each comprising one relatively standalone paper. The unifying theme is fragmentalism about truth, which is the view that the predicate “true” either expresses distinct concepts or expresses distinct properties. -/- In Chapter 1, I provide a formal development of alethic pluralism. Pluralism is the view that there are distinct truth properties associated with distinct domains of subject matter, where a truth property satisfies certain truth-characterizing principles. On behalf of pluralists, I propose an account of logic (...) and semantics that shows how they can answer central conceptual and logical challenges for their view. -/- In Chapter 2, I motivate and develop a modal account of propositions on the basis of an iterative conception of propositions, where the modality is logico-mathematical. The modal account of propositions takes the conception to motivate an inherently potential hierarchy of propositions. I show that the account helps provide satisfying solutions to the intensional paradoxes of Russell-Myhill, Kaplan, and Prior. -/- In Chapter 3, I propose that “true” is polysemous. I suggest that “true” is initially polysemous between correspondence truth and disquotational truth, and further polysemous between the meanings corresponding to the subconcepts of the concept truth generated by the indefinite extensibility of that concept. I show that the proposal provides satisfying solutions to the semantic paradoxes. (shrink)

The account of vagueness Bertrand Russell provided in his 1923 paper, entitled simply “Vagueness” (see Russell [1923]1997), has been thought by some to be inconsistent. One main objection, raised by Timothy Williamson (1994), is that Russell’s attempt early in the paper to distinguish vagueness from generality is at odds with the definition of vagueness he presents later in the same paper. It is as if, as Williamson puts it, Russell “backslides” from his previous distinction (1994, 60), resulting in a conflation (...) of generality and vagueness that is at best problematic for a rigorous account of the phenomenon of vagueness. In this paper, I will defend Russell from this particular objection. While his 1923 paper may not be as clear at various points as one might hope, I do believe it is possible to construct a single theory of vagueness that can be applied equally well to his earlier and later discussions. Thus, Russell’s view is not ultimately inconsistent. In this paper, I will first present the interpretation of Russell’s concept of vagueness that falls prey to the charge of conflating vagueness and generality. Once the problem is clear, I will present an alternative interpretation, one that arises from certain reflections on G. W. Leibniz’s theory of perception. This Leibnizian interpretation of Russell, I will argue, resolves the apparent contradiction in Russell’s account of vagueness. (shrink)

This thesis analyses the ontological nature of quantum particles. In it I argue that quantum particles, despite their indistinguishability, are objects in much the same way as classical particles. This similarity provides an important point of continuity between classical and quantum physics. I consider two notions of indistinguishability, that of indiscernibility and permutation symmetry. I argue that neither sort of indistinguishability undermines the identity of quantum particles. I further argue that, when we understand in distinguishability in terms of permutation symmetry, (...) classical particles are just as indistinguishable as quantum particles; for classical physics also possesses permutation symmetry. (shrink)

I argue for an account of vagueness according to which the root of vagueness lies not in the type of semantic-value that is best associated with an expression, but in the type of linguistic practice that renders the expression meaningful. I suggest, in particular, that conventions about how to use sentences involving attributions of vague predicates to borderline cases prevail to a lesser degree than conventions about how to use sentences involving attributions of vague predicates to clear cases.

Questions concerning the nature of representation and what representations are about have been a staple of Western philosophy since Aristotle. Recently, these same questions have begun to concern neuroscientists, who have developed new techniques and theories for understanding how the locus of neurobiological representation, the brain, operates. My dissertation draws on philosophy and neuroscience to develop a novel theory of representational content.

Putnam’s semantic argument against the BIV hypothesis and Sosa’s argument against dream skepticism based on the imagination model of dreaming share some important structural features. In both cases the skeptical option is supposed to be excluded because preconditions of its intelligibility are not fulfilled (affirmation and belief in the dream scenario, thought and reference in the BIV scenario). Putnam’s reasoning is usually interpreted differently, as a classic case of deception, but this feature is not essential. I propose to interpret BIV’s (...) utterances as cases of reference failure best captured by truth-value gaps. Both anti-skeptical strategies are then vulnerable to the same type of objections (how do we know what state we are in or how do we know what kind of language do we speak). (shrink)

Counterfactuals are somewhat tolerant. Had Socrates been at least six feet tall, he need not have been exactly six feet tall. He might have been a little taller—he might have been six one or six two. But while he might have been a little taller, there are limits to how tall he would have been. Had he been at least six feet tall, he would not have been more than a hundred feet tall, for example. Counterfactuals are not just tolerant, (...) then, but bounded. This paper presents a surprising paradox: If counterfactuals are tolerant and bounded, then we can prove a flat contradiction using natural rules of inference. Something has to go then. But what? (shrink)

In his essay ‘“Wang’s Paradox”’, Crispin Wright proposes a solution to the Sorites Paradox (in particular, the form of it he calls the ‘Paradox of Sharp Boundaries’) that involves adopting intuitionistic logic when reasoning with vague predicates. He does not give a semantic theory which accounts for the validity of intuitionistic logic (and the invalidity of stronger logics) in that area. The present essay tentatively makes good the deficiency. By applying a theorem of Tarski, it shows that intuitionistic logic is (...) the strongest logic that may be applied, given certain semantic assumptions about vague predicates. The essay ends with an inconclusive discussion of whether those semantic assumptions should be accepted. (shrink)

The article deals with the question of correct reconstruction of and solutions to the ancient paradoxes. Analyzing one contemporary example of a reconstruction of the so-called Crocodile Paradox, taken from Sorensen’s A Brief History of Paradox, the author shows how the original pattern of paradox could have been incorrectly transformed in its meaning by overlooking its adequate historical background. Sorensen’s quoting of Aphthonius, as the author of a certain solution to the paradox, seems to be a systematic failure since the (...) time of Politiano’s erroneous attributing it to Aphthonius. In the conclusion, the author claims that neglecting the historical background of the ancient paradoxes into account, we are neither able to evaluate their modern interpretations as adequate nor their solutions as successful. (shrink)