Discussions of higher-order vagueness rarely define what it is for a term to have nth-order vagueness for n>2. This paper provides a rigorous definition in a framework analogous to possible worlds semantics; it is neutral between epistemic and supervaluationist accounts of vagueness. The definition is shown to have various desirable properties. But under natural assumptions it is also shown that 2nd-order vagueness implies vagueness of all orders, and that a conjunction can have 2nd-order vagueness (...) even if its conjuncts do not. Relations between the definition and other proposals are explored; reasons are given for preferring the present proposal. (shrink)

There is a trade-off between specificity and accuracy in existing models of belief. Descriptions of agents in the tripartite model, which recognizes only three doxastic attitudes—belief, disbelief, and suspension of judgment—are typically accurate, but not sufficiently specific. The orthodox Bayesian model, which requires real-valued credences, is perfectly specific, but often inaccurate: we often lack precise credences. I argue, first, that a popular attempt to fix the Bayesian model by using sets of functions is also inaccurate, since it requires us to (...) have interval-valued credences with perfectly precise endpoints. We can see this problem as analogous to the problem of higher order vagueness. Ultimately, I argue, the only way to avoid these problems is to endorse Insurmountable Unclassifiability. This principle has some surprising and radical consequences. For example, it entails that the trade-off between accuracy and specificity is in-principle unavoidable: sometimes it is simply impossible to characterize an agent’s doxastic state in a way that is both fully accurate and maximally specific. What we can do, however, is improve on both the tripartite and existing Bayesian models. I construct a new model of belief—the minimal model—that allows us to characterize agents with much greater specificity than the tripartite model, and yet which remains, unlike existing Bayesian models, perfectly accurate. (shrink)

Sample chapter from H. Asgeirsson, The Nature and Value of Vagueness in the Law (Hart Publishing, 2020), in which I present and partially defend a version of what has come to be called the communicative-content theory of law. Book abstract: Lawmaking is – paradigmatically – a type of speech act: people make law by saying things. It is natural to think, therefore, that the content of the law is determined by what lawmakers communicate. However, what they communicate is sometimes (...) vague and, even when it is clear, the content itself is sometimes vague. The monograph examines the nature and consequences of these two linguistic sources of indeterminacy in the law with the aim of providing plausible answers to three related questions: In virtue of what is the law vague? What might be good about vague law? How should courts resolve cases of vagueness? (shrink)

It is natural to think that law ought not to be vague. After all, law is supposed to guide conduct, and vague law seems poorly suited to do that. Contrary to this common impression, however, a number of authors have argued that vagueness in the law is sometimes a good thing, because it is a means to achieving certain valuable legislative ends. In this article, I argue that many authors—including Timothy Endicott and Jeremy Waldron—wrongly associate vagueness with instrumental (...) roles that are really played by a closely related semantic phenomenon. (shrink)

The so-called "argument from vagueness", the clearest formulation of which is to be found in Ted Sider’s book Four-dimensionalism, is arguably the most powerful and innovative argument recently offered in support of the view that objects are four-dimensional perdurants. The argument is defective--I submit--and in a number of ways that is worth looking into. But each "defect" corresponds to a model of change that is independently problematic and that can hardly be built into the common-sense picture of the world. (...) So once all the gaps of the argument are filled in, the three-dimensionalist is left with the burden of a response that cannot rely on a passive plea for common sense. The argument is not a threat to common sense as such; it is a threat to the three-dimensionalist faithfulness to common sense. (shrink)

This paper develops a novel problem for representationalism (also known as "intentionalism"), a popular contemporary account of perception. We argue that representationalism is incompatible with supervaluationism, the leading contemporary account of vagueness. The problem generalizes to naive realism and related views, which are also incompatible with supervaluationism.

This paper addresses three problems: the problem of formulating a coherent relativism, the Sorites paradox and a seldom noticed difficulty in the best intuitionistic case for the revision of classical logic. A response to the latter is proposed which, generalised, contributes towards the solution of the other two. The key to this response is a generalised conception of indeterminacy as a specific kind of intellectual bafflement-Quandary. Intuitionistic revisions of classical logic are merited wherever a subject matter is conceived both as (...) liable to generate Quandary and as subject to a broad form of evidential constraint. So motivated, the distinctions enshrined in intuitionistic logic provide both for a satisfying resolution of the Sorites paradox and a coherent outlet for relativistic views about, e.g., matters of taste and morals. An important corollary of the discussion is that an epistemic conception of vagueness can be prised apart from the strong metaphysical realism with which its principal supporters have associated it, and acknowledged to harbour an independent insight. (shrink)

One of the most influential arguments in favour of perdurantism is the Argument from Vagueness. The argument proceeds in three stages: The first aims to establish atemporal universalism. The second presents a parallel argument in favour of universalism in the context of temporalized parthood. The third argues that diachronic universalism entails perdurantism. I offer a novel objection to the argument. I show that on the correct way of formulating diachronic universalism the principle does not entail perdurantism. On the other (...) hand, if diachronic universalism is formulated as Sider proposes, the argument fails to establish his principle, and thus perdurantism. (shrink)

I postulate that the extension of a degree adjective is fixed by implicitly accepted non-analytic reference-fixing principles (“preconceptions”) that combine appeals to paradigmatic cases with generic principles designed to expand the extension of the adjective beyond the paradigmatic range. In regular occasions of use, the paradigm and generic preconceptions are jointly satisfied and determine the existence of an extension/anti-extension pair dividing the adjective’s comparison class into two mutually exclusive and jointly exhaustive subclasses. Sorites paradoxical occasions of use are irregular occasions (...) of use in which the paradigm and generic preconceptions are not jointly satisfied. In them, the relevant degree adjective lacks an extension, and utterances of sentences containing it appearing in sorites arguments do not have truth conditions. I also postulate a probable psychology of paradigm intuitions, used in a psychological explanation of the preference for solutions of the sorites paradox on which paradigm preconceptions retain their intuitive truth-values. (shrink)

There are several different forms of comparability involving prudential values. Comparisons of values in the abstract, of realizations of some value, and of options which realize values, are distinct, and related, though not mutually exclusive. Furthermore, if rough equality is thought of as an evaluative relation in terms of which comparisons can be made, it does not imply incomparability. If it involves epistemic vagueness, this does not imply incomparability, since our not knowing which relation holds does not imply that (...) no relation holds. Finally, if it is true to some degree that some relation holds, there may be some fuzzy ordering. Given that we may not be able coherently to talk about degrees of truth, I propose an open-ended comparability condition, which takes account of rough equality, epistemic vagueness and fuzziness. (shrink)

In The Boundary Stones of Thought, Rumfitt defends classical logic against challenges from intuitionistic mathematics and vagueness, using a semantics of pre-topologies on possibilities, and a topological semantics on predicates, respectively. These semantics are suggestive but the characterizations of negation face difficulties that may undermine their usefulness in Rumfitt’s project.

E. J. Lowe; The problem of the many and the vagueness of constitution, Analysis, Volume 55, Issue 3, 1 July 1995, Pages 179–182, https://doi.org/10.1093/analys/.

It has been suggested that Marr took the three levels he famously identifies to be independent. In this paper, we argue that Marr's view is more nuanced. Specifically, we show that the view explicitly articulated in his work attempts to integrate the levels, and in doing so results in Marr attacking both reductionism and vagueness. The result is a perspective in which both high-level information-processing constraints and low-level implementational constraints play mutually reinforcing and constraining roles. We discuss our recent (...) work on Spaun—currently the world's largest functional brain model—that demonstrates the positive impact of this kind of unifying integration of Marr's levels. We argue that this kind of integration avoids his concerns with both reductionism and vagueness. In short, we suggest that the methods behind Spaun can be used to satisfy Marr's explicit interest in combining high-level functional and detailed mechanistic explanations. (shrink)

Elizabeth Barnes and J. Robert G. Williams claim to offer a new ontic theory of vagueness, the kind of theory which considers vagueness to exist not in language but in reality. This paper refutes their claim. The possible worlds they employ are ersatz possible worlds, i.e., sets of sentences. Unlike reality, they don’t contain concrete and often material objects. As a result, there is nothing in Barnes and Williams’s description of the theory that the semanticist cannot or does (...) not accept. Thus, they have failed to establish their theory as a genuine intelligible ontic alternative to semantic theories. (shrink)

This chapter discusses the defence of metaphysical indeterminacy by Elizabeth Barnes and Robert Williams and discusses a classical and bivalent theory of such indeterminacy. Even if metaphysical indeterminacy arguably is intelligible, Barnes and Williams argue in favour of it being so and this faces important problems. As for classical logic and bivalence, the chapter problematizes what exactly is at issue in this debate. Can reality not be adequately described using different languages, some classical and some not? Moreover, it is argued (...) that the classical and bivalent theory of Barnes and Williams does not avoid the problems that arise for rival theories. (shrink)

Scott Soames has recently argued that the fact that lawmakers and other legal practitioners regard vagueness as having a valuable power-delegating function gives us good reason to favor one theory of vagueness over another. If Soames is right, then facts about legal practice can in an important sense adjudicate between rival theories of vagueness. I argue that due to what I call the “Gappiness Problem” – raised by recent critics of the “communicative-content theory of law” – we (...) have to give up the one premise of Soames’s argument that he seems to take to be uncontroversial: that the legal content of a statute or constitutional clause is identical with, or constituted by, its communicative content. I provide a sketch of my own account of legal content and show how it provides a response to the Gappiness Problem. This account, however, does not suffice to vindicate Soames’s argument. I conclude by arguing that my point about Soames’s argument is generalizable. (shrink)

This paper is an attempt to show that the subvaluation theory isnot a good theory of vagueness. It begins with a short review of supervaluation and subvaluation theories and procedes to evaluate the subvaluation theory. Subvaluationism shares all the main short-comings of supervaluationism.Moreover, the solution to the sorites paradox proposed by subvaluationists isnot satisfactory. There is another solution which subvaluationists could availthemselves of, but it destroys the whole motivation for using a paraconsistentlogic and is not different from the one (...) offered by supervaluationism. (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.

A common objection to theories of vagueness based on fuzzy logics centres on the idea that assigning a single numerical degree of truth -- a real number between 0 and 1 -- to each vague statement is excessively precise. A common objection to Bayesian epistemology centres on the idea that assigning a single numerical degree of belief -- a real number between 0 and 1 -- to each proposition is excessively precise. In this paper I explore possible parallels between (...) these objections. In particular I argue that the only good objection along these lines to fuzzy theories of vagueness does not translate into a good objection to Bayesian epistemology. An important part of my argument consists in drawing a distinction between two different notions of degree of belief, which I call dispositional degree of belief and epistemic degree of belief. (shrink)

The problem of artificial precision is a major objection to any theory of vagueness based on real numbers as degrees of truth. Suppose you are willing to admit that, under sufficiently specified circumstances, a predication of “is red” receives a unique, exact number from the real unit interval [0, 1]. You should then be committed to explain what is it that determines that value, settling for instance that my coat is red to degree 0.322 rather than 0.321. In this (...) note I revisit the problem in the important case of Łukasiewicz infinite-valued propositional logic that brings to the foreground the rôle of maximally consistent theories. I argue that the problem of artificial precision, as commonly conceived of in the literature, actually conflates two distinct problems of a very different nature. (shrink)

This book is a must-read for researchers interested in taking a high-level, non-mechanistic approach to answering age-old fundamental questions in the brain ...

In this paper, I will be primarily concerned with moral issues regarding future people and the environment. When it comes to the future, we have deontological and epistemic limitations. The closer to the present, the higher the certainty and the knowledge we have about facts. Thus, when we intend to find moral clarity regarding a future scenario, we deal with an inverse relation between certainty and time. The main problem is that most ways of dealing with moral issues about future (...) scenarios do not address this relation, and rather focus on things that seem to simplify and clarify the uncertainties of the future. In response to this, I propose a different approach, one that operates neutrally and timelessly dealing with the uncertainties of the future while providing moral groundings that can help to clarify the future’s state of moral vagueness. (shrink)

This article provides an intuitive semantic account of a new logic for comparisons (CL), in which atomic statements are assigned both a classical truth-value and a “how much” value or extension in the range [0, 1]. The truth-value of each comparison is determined by the extensions of its component sentences; the truth-value of each atomic depends on whether its extension matches a separate standard for its predicate; everything else is computed classically. CL is less radical than Casari’s comparative logics, in (...) that it does not allow for the formation of comparative statements out of truth-functional molecules. It is argued that CL provides a better analysis of predicate vagueness than classical logic, fuzzy logic or supervaluation theory. (shrink)

Paraconsistent responses to vagueness are often thought to represent a revision of logical theory that is too radical to be defensible. The paracomplete logic of supervaluationism, SpV, is not only taken to be more conservative but is also commonly said to 'preserve classical logic'. This chapter argues that this is wrong on both counts. The paraconsistent logic SbV, or subvaluationism, is no less conservative than SpV nor more so. In the end both logics offer equally compelling theoretical approaches to (...) vagueness. Each approach is also equally objectionable, with neither providing an adequate account of vagueness, but this criticism arises from a feature shared by each approach that is independent of their paracompleteness or paraconsistency per se. For all that has been said, a paraconsistent approach, and the associated recourse to truth-value gluts, remains a contender in accounting for vagueness. (shrink)

We motivate and formalize the idea of sameness by default: two objects are considered the same if they cannot be proved to be different. This idea turns out to be useful for a number of widely different applications, including natural language processing, reasoning with incomplete information, and even philosophical paradoxes. We consider two formalizations of this notion, both of which are based on Reiter’s Default Logic. The first formalization is a new relation of indistinguishability that is introduced by default. We (...) prove that the corresponding default theory has a unique extension, in which every two objects are indistinguishable if and only if their non-equality cannot be proved from the known facts. We show that the indistinguishability relation has some desirable properties: it is reflexive, symmetric, and, while not transitive, it has a transitive “flavor.” The second formalization is an extension (modification) of the ordinary language equality by a similar default: two objects are equal if and only if their non-equality cannot be proved from the known facts. It appears to be less elegant from a formal point of view. In particular, it gives rise to multiple extensions. However, this extended equality is better suited for most of the applications discussed in this paper. (shrink)

I can say that a building is tall and you can understand me, even if neither of us has any clear idea exactly how tall a building must be in order to count as tall. This mundane fact poses a problem for the view that successful communication consists in the hearer’s recognition of the proposition a speaker intends to assert. The problem cannot be solved by the epistemicist’s usual appeal to anti-individualism, because the extensions of vague words like ‘tall’ are (...) contextually fluid and can be constrained significantly by speakers’ intentions. The problem can be seen as a special case of a more general problem concerning what King has called “felicitous underspecification.” Traditional theories of vagueness offer nothing that can help with this problem. Appeals to diagonalization do not help either. A more radical solution is needed. (shrink)

Development of decision-support and intelligent agent systems necessitates mathematical descriptions of uncertainty and fuzziness in order to model vagueness. This paper seeks to present an outline of Peirce’s triadic logic as a practical new way to model vagueness in the context of artificial intelligence. Charles Sanders Peirce was an American scientist–philosopher and a great logician whose triadic logic is a culmination of the study of semiotics and the mathematical study of anti-Cantorean model of continuity and infinitesimals. After presenting (...) Peircean semiotics within AI perspective, a mathematical formulation of a Peircean triadic set is given in relationship with classical and fuzzy sets. Using basic logical operators, all possible respective implication operators, bi-equivalence operators, valid rules of inference, and associative, distributive and commutative logical properties are derived and verified through the truth function approach. In order to suggest practical directions, aggregation operators for Peirce’s triadic logic have been formulated. A mathematical formulation of a medical diagnostic problem and ER diagram of a library management system using Peirce’s triadic relation show potential for further applications of the proposed triadic set and triadic logic. Alongside, a classical AI game—The Wumpus World—is implemented to show practical efficacy in comparison with binary implementation. Besides giving some preliminary formulations for trichotomous set theory and definition of finite automaton, development of hybrid architectures for intelligent agents and evolutionary computations are discussed as potential practical avenues for Peirce’s triadic logic. (shrink)