I develop a theory of counterfactuals about relative computability, i.e. counterfactuals such as 'If the validity problem were algorithmically decidable, then the halting problem would also be algorithmically decidable,' which is true, and 'If the validity problem were algorithmically decidable, then arithmetical truth would also be algorithmically decidable,' which is false. These counterfactuals are counterpossibles, i.e. they have metaphysically impossible antecedents. They thus pose a challenge to the orthodoxy about counterfactuals, which would treat them as uniformly true. What’s more, I (...) argue that these counterpossibles don’t just appear in the periphery of relative computability theory but instead they play an ineliminable role in the development of the theory. Finally, I present and discuss a model theory for these counterfactuals that is a straightforward extension of the familiar comparative similarity models. (shrink)

In this book review, I summarize the main argument of Tilo Wesche's book "Die Rechte der Natur: Vom nachhaltigen Eigentum" (The rights of Nature: On sustainable ownership) and conclude with a critical appraisal.

Some moral value is transparent just in case an agent with average mental capacities can feasibly come to know whether some entity does, or does not, possess that value. In this paper, I consider whether legitimacy—that is, the property of exercises of political power to be permissible—is transparent. Implicit in much theorising about legitimacy is the idea that it is. I will offer two counter-arguments. First, injustice can defeat legitimacy, and injustice can be intransparent. Second, legitimacy can play a critical (...) function in our practical thought, which sometimes requires intransparency. (shrink)

Studying consciousness requires contrasting conscious and unconscious perception. While many studies have reported unconscious perceptual effects, recent work has questioned whether such effects are genuinely unconscious, or whether they are due to weak conscious perception. Some philosophers and psychologists have reacted by denying that there is such a thing as unconscious perception, or by holding that unconscious perception has been previously overestimated. This article has two parts. In the first part, I argue that the most significant attack on unconscious perception (...) commits the criterion content fallacy: the fallacy of interpreting evidence that observers were conscious of something as evidence that they were conscious of the task-relevant features of the stimuli. In the second part, I contend that the criterion content fallacy is prevalent in consciousness research. For this reason, I hold that if unconscious perception exists, scientists studying consciousness could routinely underestimate it. I conclude with methodological recommendations for moving the debate forward. (shrink)

In this paper, I examine Alston's arguments for doxastic involuntarism. Alston fails to distinguish (i) between volitional and executional lack of control, and (ii) between compatibilist and libertarian control. As a result, he fails to notice that, if one endorses a compatibilist notion of voluntary control, the outcome is a straightforward and compelling case for doxastic voluntarism. Advocates of involuntarism have recently argued that the compatibilist case for doxastic voluntarism can be blocked by pointing out that belief is never intentional. (...) In response to this strategy, I distinguish between two types of intentionality and argue that belief is no less intentional than action is. (shrink)

A major part of philosophical work is engagement with argumentative texts. Engaging with an argumentative text involves correctly identifying the arguments presented in this text. In the context of teaching philosophy in school, the difficulty of correctly identifying arguments in philosophical texts is often underestimated. In this paper, I focus on one specific problem with argument identification that has been neglected in philosophy didactics thus far: the problem that there are many non-argumentative phenomena in an argumentative text that are easily (...) misidentified as expressing (part of) an argument. It is easy to fall for such phenomena if one is not aware of this problem, thereby misinterpreting the author’s intentions. This paper aims to present and discuss such phenomena, as well as to provide guidelines on how to help students recognize them. (shrink)

Opponents to consciousness in fish argue that fish do not feel pain because they do not have a neocortex, which is a necessary condition for feeling pain. A common counter-argument appeals to the multiple realizability of pain: while a neocortex might be necessary for feeling pain in humans, pain might be realized differently in fish. This paper argues, first, that it is impossible to find a criterion allowing us to demarcate between plausible and implausible cases of multiple realization of pain (...) without running into a circular argument. Second, opponents to consciousness in fish cannot be provided with reasons to believe in the multiple realizability of pain. I conclude that the debate on the existence of pain in fish is impossible to settle by relying on the multiple realization argument. (shrink)

To study (un)conscious perception and test hypotheses about consciousness, researchers need procedures for determining whether subjects consciously perceive stimuli or not. This article is an introduction to a family of procedures called ‘confidence-based procedures’, which consist in interpreting metacognitive indicators as indicators of consciousness. I assess the validity and accuracy of these procedures, and answer a series of common objections to their use in consciousness research. I conclude that confidence-based procedures are valid for assessing consciousness, and, in most cases, accurate (...) enough for our practical and scientific purposes. (shrink)

Whether the prefrontal cortex is part of the neural substrates of consciousness is currently debated. Against prefrontal theories of consciousness, many have argued that neural activity in the prefrontal cortex does not correlate with consciousness but with subjective reports. We defend prefrontal theories of consciousness against this argument. We surmise that the requirement for reports is not a satisfying explanation of the difference in neural activity between conscious and unconscious trials, and that prefrontal theories of consciousness come out of this (...) debate unscathed. (shrink)

As for most measurement procedures in the course of their development, measures of consciousness face the problem of coordination, i.e., the problem of knowing whether a measurement procedure actually measures what it is intended to measure. I focus on the case of the Perceptual Awareness Scale to illustrate how ignoring this problem leads to ambiguous interpretations of subjective reports in consciousness science. In turn, I show that empirical results based on this measurement procedure might be systematically misinterpreted.

A uniform construction for sequent calculi for finite-valued first-order logics with distribution quantifiers is exhibited. Completeness, cut-elimination and midsequent theorems are established. As an application, an analog of Herbrand’s theorem for the four-valued knowledge-representation logic of Belnap and Ginsberg is presented. It is indicated how this theorem can be used for reasoning about knowledge bases with incomplete and inconsistent information.

According to a standard criticism, Robert Brandom's “normative pragmatics”, i.e. his attempt to explain normative statuses in terms of practical attitudes, faces a dilemma. If practical attitudes and their interactions are specified in purely non-normative terms, then they underdetermine normative statuses; but if normative terms are allowed into the account, then the account becomes viciously circular. This paper argues that there is no dilemma, because the feared circularity is not vicious. While normative claims do exhibit their respective authors' practical attitudes (...) and thereby contribute towards establishing the normative statuses they are about, this circularity is not a mark of Brandom's explanatory strategy but a feature of social practice of which we theorists partake. (shrink)

Consciousness is scientifically challenging to study because of its subjective aspect. This leads researchers to rely on report-based experimental paradigms in order to discover neural correlates of consciousness (NCCs). I argue that the reliance on reports has biased the search for NCCs, thus creating what I call 'methodological artefacts'. This paper has three main goals: first, describe the measurement problem in consciousness science and argue that this problem led to the emergence of methodological artefacts. Second, provide a critical assessment of (...) the NCCs put forward by the global neuronal workspace theory. Third, provide the means of dissociating genuine NCCs from methodological artefacts. (shrink)

In this paper we discuss the new Tweety puzzle. The original Tweety puzzle was addressed by approaches in non-monotonic logic, which aim to adequately represent the Tweety case, namely that Tweety is a penguin and, thus, an exceptional bird, which cannot fly, although in general birds can fly. The new Tweety puzzle is intended as a challenge for probabilistic theories of epistemic states. In the first part of the paper we argue against monistic Bayesians, who assume that epistemic states can (...) at any given time be adequately described by a single subjective probability function. We show that monistic Bayesians cannot provide an adequate solution to the new Tweety puzzle, because this requires one to refer to a frequency-based probability function. We conclude that monistic Bayesianism cannot be a fully adequate theory of epistemic states. In the second part we describe an empirical study, which provides support for the thesis that monistic Bayesianism is also inadequate as a descriptive theory of cognitive states. In the final part of the paper we criticize Bayesian approaches in cognitive science, insofar as their monistic tendency cannot adequately address the new Tweety puzzle. We, further, argue against monistic Bayesianism in cognitive science by means of a case study. In this case study we show that Oaksford and Chater’s (2007, 2008) model of conditional inference—contrary to the authors’ theoretical position—has to refer also to a frequency-based probability function. (shrink)

We investigate a lattice of conditional logics described by a Kripke type semantics, which was suggested by Chellas and Segerberg – Chellas–Segerberg (CS) semantics – plus 30 further principles. We (i) present a non-trivial frame-based completeness result, (ii) a translation procedure which gives one corresponding trivial frame conditions for arbitrary formula schemata, and (iii) non-trivial frame conditions in CS semantics which correspond to the 30 principles.

The aim of this paper is to emphasize the fact that for all finitely-many-valued logics there is a completely systematic relation between sequent calculi and tableau systems. More importantly, we show that for both of these systems there are al- ways two dual proof sytems (not just only two ways to interpret the calculi). This phenomenon may easily escape one’s attention since in the classical (two-valued) case the two systems coincide. (In two-valued logic the assignment of a truth value and (...) the exclusion of the opposite truth value describe the same situation.). (shrink)

The current global COVID-19 pandemic has led to a deep and multidimensional crisis across all sectors of society. As countries contemplate their mobility and social-distancing policy restrictions, we have a unique opportunity to re-imagine the deliberative frameworks and value priorities in our food systems. Pre-pandemic food systems at global, national, regional and local scales already needed revision to chart a common vision for sustainable and ethical food futures. Re-orientation is also needed by the relevant sciences, traditionally siloed in their disciplines (...) and without adequate attention paid to how the food system problem is variously framed by diverse stakeholders according to their values. From the transdisciplinary perspective of food ethics, we argue that a post-pandemic scheme focused on bottom-up, regional, cross-sectoral and non-partisan deliberation may provide the re-orientation and benchmarks needed for not only more sustainable, but also more ethical food futures. (shrink)

According to the global neuronal workspace model of consciousness, consciousness results from the global broadcast of information throughout the brain. The global neuronal workspace is mainly constituted by a fronto-parietal network. The anterior insular cortex is part of this global neuronal workspace, but the function of this region has not yet been defined within the global neuronal workspace model of consciousness. In this review, I hypothesize that the anterior insular cortex implements a cross-modal priority map, the function of which is (...) to determine priorities for the processing of information and subsequent entrance in the global neuronal workspace. (shrink)

Entailment in propositional Gödel logics can be defined in a natural way. While all infinite sets of truth values yield the same sets of tautologies, the entailment relations differ. It is shown that there is a rich structure of infinite-valued Gödel logics, only one of which is compact. It is also shown that the compact infinite-valued Gödel logic is the only one which interpolates, and the only one with an r.e. entailment relation.

Any intermediate propositional logic can be extended to a calculus with epsilon- and tau-operators and critical formulas. For classical logic, this results in Hilbert’s $\varepsilon $ -calculus. The first and second $\varepsilon $ -theorems for classical logic establish conservativity of the $\varepsilon $ -calculus over its classical base logic. It is well known that the second $\varepsilon $ -theorem fails for the intuitionistic $\varepsilon $ -calculus, as prenexation is impossible. The paper investigates the effect of adding critical $\varepsilon $ - (...) and $\tau $ -formulas and using the translation of quantifiers into $\varepsilon $ - and $\tau $ -terms to intermediate logics. It is shown that conservativity over the propositional base logic also holds for such intermediate ${\varepsilon \tau }$ -calculi. The “extended” first $\varepsilon $ -theorem holds if the base logic is finite-valued Gödel–Dummett logic, and fails otherwise, but holds for certain provable formulas in infinite-valued Gödel logic. The second $\varepsilon $ -theorem also holds for finite-valued first-order Gödel logics. The methods used to prove the extended first $\varepsilon $ -theorem for infinite-valued Gödel logic suggest applications to theories of arithmetic. (shrink)

Like many other philosophical disciplines, ethics is sometimes highly abstract. And many key notions of the discipline are vague, ambiguous or both. Abstractness, vagueness, and ambiguity invite confusion. My objective in this paper is to draw attention to a serious problem that, despite being widespread, has so far remained largely unrecognized: the confusion of different questions in teaching ethics. This confusion occurs, for example, when a philosopher’s viewpoint is presented as an answer to one question, but in fact, the philosopher (...) is addressing a different question with that viewpoint. In the first part of this paper, I will present and clarify several ethical questions that are often confused, and point out damaging consequences that the confusion of such questions entails. In the second part, I will demonstrate the confusion of ethical questions by drawing attention to cases of confused teaching of Schopenhauer’s ethics. Finally, for those interested, I outline how Schopenhauer’s ethics could be taught without confusion. (shrink)

To study consciousness, scientists need to determine when participants are conscious and when they are not. They do so with consciousness detection procedures. A recurring skeptical argument against those procedures is that they cannot be calibrated: there is no way to make sure that detection outcomes are accurate. In this article, I address two main skeptical arguments purporting to show that consciousness scientists cannot calibrate detection procedures. I conclude that there is nothing wrong with calibration in consciousness science.

Psychiatric research is in crisis because of repeated failures to discover new drugs for mental disorders. Lack of measurement validity could partly account for these failures. If researchers do not actually measure the effects of drugs on the disorders they aim to investigate, one should expect suboptimal treatment outcomes. I argue that this is the case, focusing on depression, and fear & anxiety disorders. In doing so, I show how psychiatric research illustrates a more general phenomenon that I call “validity (...) drift.” A validity drift occurs when, in the course of developing new measurement procedures, researchers end up studying something different from what they originally aimed to study. I analyze the different ways in which scientists attempt to validate procedures for measuring mental disorders for the purpose of testing drugs in animal models. I show how those validation efforts might fail, thereby leading to validity drifts. Overall, this analysis highlights the complex interplay between the development of new measurement procedures, their calibration, and scientific theories of the target phenomena. (shrink)

Local theories of consciousness state that one is conscious of a feature if it is adequately represented and processed in sensory brain areas, given some background conditions. We challenge the core prediction of local theories based on long-lasting postdictive effects demonstrating that features can be represented for hundreds of milliseconds in perceptual areas without being consciously perceived. Unlike previous empirical data aimed against local theories, localists cannot explain these effects away by conjecturing that subjects are phenomenally conscious of features that (...) they cannot report. We also discuss alternative explanations that localists could offer. (shrink)

Anosognosia for visual deficits—cases where significant visual deficits go unnoticed—challenges the view that our own conscious experiences are what we know best. We review these widespread and striking failures of awareness. Anosognosia can occur with total blindness, visual abnormalities induced by brain lesions, and eye diseases. We show that anosognosia for visual deficits is surprisingly widespread. Building on previous accounts, we introduce a framework showing how apparently disparate forms of anosognosia fit together. The central idea is that, to notice a (...) deficit, individuals need to form expectations about normal vision, compare expectations and visual input, and judge any mismatch at the metacognitive level. A failure in any of these three steps may lead to unawareness of visual deficits. (shrink)

Is perceptual processing in dedicated sensory areas sufficient for conscious perception? Localists say ‘Yes—given some background conditions.’ Prefrontalists say ‘No: conscious perceptual experience requires the involvement of prefrontal structures.’ I review the evidence for prefrontalism. I start by presenting correlational evidence. In doing so, I answer the ‘report argument’, according to which the apparent involvement of the prefrontal cortex in consciousness stems from the requirement for reports. I then review causal evidence for prefrontalism and answer the ‘lesion argument’, which purports (...) to show that prefrontalism is wrong because lesions to the prefrontal cortex do not abolish consciousness. I conclude that multiple sources of evidence converge toward the view that the prefrontal cortex plays a significant role in consciousness. (shrink)

The question whether a constitutive linguistic norm can be prescriptive is central to the debate on the normativity of meaning. Recently, the author has attempted to defend an affirmative answer, pointing to how speakers sporadically invoke constitutive linguistic norms in the service of linguistic calibration. Such invocations are clearly prescriptive. However, they are only appropriate if the invoked norms are applicable to the addressed speaker. But that can only be the case if the speaker herself generally accepts them. This qualification (...) has led critics to argue that if an addressed speaker’s acceptance is a necessary condition for legitimate prescriptions (and reproach for failure to adhere to them), then the account becomes unable to underwrite actual normativity. Moreover, critics argue, a danger of vicious circularity arises from the calibration account. This paper shows that once a vantage point within the calibration practice is accepted, the criticisms lose their force. It then explores why a theorist might reject such a perspective and suggests, as a plausible candidate, implicit Humean assumptions about the proper explanation of (linguistic) action. The paper ends by sketching a way forward for the debate on the normativity of meaning in light of this diagnosis. (shrink)

In our contemporary world, the rights of nature have become an important legal device for environmental protection. Some of the most influential rights of nature frameworks can be found in non-Western contexts and have been strongly influenced by ecocentric accounts of nature. This article addresses the question of whether rights of nature can be implemented in Western contexts as well, focusing in particular on Europe. It first examines ecocentric justifications of the rights of nature and discusses two possible non-ecocentric alternatives. (...) Second, two models for implementing rights of nature—the nature’s rights model and the legal personhood model—are compared to demonstrate how different combinations of elements from both models can fit different socio-cultural contexts, including Western ones. (shrink)

The aim of this paper is to show that the French philosopher and historian of science Abel Rey played a more influential role in the formative phase of the Vienna Circle than hitherto supposed. On the whole, it will be argued that Rey's contribution had political impact. His interpretation of "modern physics" in 1907 in the face of the alleged "bankruptcy of science" should be appreciated as a masterpiece of applied enlightenment thought. As such, it was especially paradigmatic for Philipp (...) Frank's "positivist" defense of the theory of relativity and quantum mechanics against the irrationalist tendencies of the 1920s and 1930s. (shrink)

A construction principle for natural deduction systems for arbitrary, finitely-many-valued first order logics is exhibited. These systems are systematically obtained from sequent calculi, which in turn can be automatically extracted from the truth tables of the logics under consideration. Soundness and cut-free completeness of these sequent calculi translate into soundness, completeness, and normal-form theorems for natural deduction systems.

A general class of labeled sequent calculi is investigated, and necessary and sufficient conditions are given for when such a calculus is sound and complete for a finite -valued logic if the labels are interpreted as sets of truth values. Furthermore, it is shown that any finite -valued logic can be given an axiomatization by such a labeled calculus using arbitrary "systems of signs," i.e., of sets of truth values, as labels. The number of labels needed is logarithmic in the (...) number of truth values, and it is shown that this bound is tight. (shrink)

Some European countries legally recognise a “right to roam”—a right to freely traverse across land, even if privately owned. Political philosophers have paid little attention to the right, and have often conceptualised property rights to include strong claim-rights to exclude others. I offer an account of the right to roam, and consider whether it can be philosophically justified on a left-liberal account of property. After finding a defence in terms of the interests served by the right lacking, I suggest that (...) the most promising defence of the right to roam is that it serves as a symbolic reminder of a fundamental type of social equality. (shrink)

Negative subjective reports such as “I didn’t see the stimulus” can be interpreted as indicating either that the subject didn’t see the stimulus, or as indicating that, while the subject did see the stimulus, the strength of sensory signals associated with the stimulus fell below a conservative criterion for answering “seen”. Determining which of these two interpretations is correct is the criterion problem. I present two ways in which researchers can solve this problem. But there’s more. What I call the (...) “new criterion problem” consists in determining whether criteria effects reflect perceptual changes, or changes in response strategy. Through case studies, I argue that this new version of the problem can be solved as well, although there is currently no systematic way to solve it. I conclude that criterion problems do not constitute good reasons for skepticism about the scientific study of consciousness. (shrink)

Newtons experimentum crucis hat ein komplementares Gegenstück, d.h. ein Experiment, in dem die Rollen von Licht und Schatten genau ausgetauscht sind. Statt wie Newton in der Dunkelkammer zu experimentieren, müssen wir das Komplement des experimentum crucis in einer Streulichtkammer aufbauen (deren Wände sog. Lambertstrahler sind). Wenn es dieses umgestülpte Experiment wirklich gibt, dann liefert es für jeden newtonischen Beweis einen umgestülpten Gegenbeweis, dessen Konklusion die Heterogenitat der Schatten wäre (also die Behauptung, dass nicht weißes Licht, sondern schwarze Schatten eine heterogene (...) Mischung verschiedenfarbiger Strahlen mit unterschiedlichen Brechungseigenschaften seien). Dass Newtons experimentum crucis in diesem Sinne umgestülpt werden kann, wird von Newtons eigener Theorie impliziert. Mehr noch, inzwischen ist der empirische Nachweis der Umstülpung gelungen. (shrink)

The present paper is concerned with Helmholtz’s theory of measurement. It will be argued that an adequate understanding of this theory depends on how Helmholtz’s application of the concepts of perception and coincidence is interpreted. In contrast both to conventionalist and Kantian readings of Helmholtz’s theory, a more realistic interpretation will be suggested.

Critical realism is a frequently mentioned, but not very well-known, late nineteenth-/early twentieth-century philosophical tradition. Having its roots in Kantian epistemology, critical realism is best characterized as a revisionist approach toward the original Kantian doctrine. Its most outstanding thesis is the idea that Kantian things-in-themselves are knowable. This idea was—at least implicitly—suggested by thinkers such as Alois Riehl, Wilhelm Wundt, and Oswald Külpe. Interestingly enough, the philosophical position of the early Moritz Schlick stands in the critical realist tradition as well. (...) As will be outlined in the course of this paper, both Schlick’s magnum opus General Theory of Knowledge (1918) and his seminal Space and Time in Contemporary Physics (1917) are based on the assumption that the objects of science are relations and that relations have the status of Kantian things-in-themselves. By way of conclusion, I shall point out that this— more or less directly—leads to the current debate over ‘structural’ realism. (shrink)

It is shown that Gqp↑, the quantified propositional Gödel logic based on the truth-value set V↑ = {1 - 1/n : n≥1}∪{1}, is decidable. This result is obtained by reduction to Büchi's theory S1S. An alternative proof based on elimination of quantifiers is also given, which yields both an axiomatization and a characterization of Gqp↑ as the intersection of all finite-valued quantified propositional Gödel logics.

For several decades, intercultural philosophers have produced an extensive body of scholarly work aimed at mutual intercultural understanding. They have focused on the ideal of intercultural dialogue that is supported by dialogue principles and virtuous attitudes. However, this ideal is challenged by decolonial scholarship as one which neglects power inequalities. Decolonial scholars have emphasized the differences between cultures and worldviews, shifting the focus to colonial history and radical alterity. In return, intercultural philosophers have worried about the very possibility of dialogue (...) and mutual understanding in frameworks that use coloniality as their singular pole of analysis. In this paper, we explore the complex relations between decolonial and intercultural philosophies. While we diagnose tensions between both intellectual discourses, we argue that these tensions turn out to be productive: for intercultural philosophers, decolonial challenges provide an opportunity to critically rethink ideals of equitable dialogue in light of colonial inequity and its deep entrenchment in global philosophical encounters. For decolonial scholars, intercultural philosophies provide an opportunity to sharpen positive proposals of equitable encounters beyond the critique of current forms of colonial domination. Rather than developing a general compromise, we propose a contextualist strategy, highlighting that different situations require different responses that can be strongly confrontational or dialogical in character. Decolonial and intercultural motifs serve different functions in the articulation of a critical global philosophy and can sharpen each other without integrating into a middle ground that is “a little bit intercultural” and “a little bit decolonial”. (shrink)

It is commonly held that the ascription of truth to a sentence is intersubstitutable with that very sentence. However, the simplest subclassical logics available to proponents of this view, namely K3 and LP, are hopelessly weak for many purposes. In this article, I argue that this is much more of a problem for proponents of LP than for proponents of K3. The strategies for recapturing classicality offered by proponents of LP are far less promising than those available to proponents of (...) K3. This undermines the ability of proponents LP to engage in public reasoning in classical domains. (shrink)

The first-order temporal logics with □ and ○ of time structures isomorphic to ω (discrete linear time) and trees of ω-segments (linear time with branching gaps) and some of its fragments are compared: the first is not recursively axiomatizable. For the second, a cut-free complete sequent calculus is given, and from this, a resolution system is derived by the method of Maslov.

This chapter presents the perceptual reality monitoring theory of consciousness (PRM). PRM is a higher-order theory of consciousness. It holds that consciousness involves monitoring the reliability of one’s own sensory signals. I explain how a perceptual reality monitoring mechanism computes the higher order representations that are crucial for consciousness. While PRM accounts for the difference between conscious and unconscious states, it does not explain, on its own, why experiences feel the way they do—the phenomenal character of experience. PRM is compatible (...) with multiple theories of phenomenal character. Here, I show how to combine it with ‘Mental Quality Space’ theory. I finish by presenting empirical evidence for PRM, as well as some of its predictions. (shrink)

Having a confirmation bias sometimes leads us to hold inaccurate beliefs. So, the puzzle goes: why do we have it? According to the influential argumentative theory of reasoning, confirmation bias emerges because the primary function of reason is not to form accurate beliefs, but to convince others that we’re right. A crucial prediction of the theory, then, is that confirmation bias should be found only in the reasoning domain. In this article, we argue that there is evidence that confirmation bias (...) does exist outside the reasoning domain. This undermines the main evidential basis for the argumentative theory of reasoning. In presenting the relevant evidence, we explore why having such confirmation bias may not be maladaptive. (shrink)

The text introduces the concept behind the Proceedings of the 2018 ZiF Workshop “Studying Migration Policies at the Interface between Empirical Research and Normative Analysis”. It explains why there is a need to study migration policies across disciplines, includes a short note on the current literature, and provides a look back at the workshop. DOI:10.17879/15199624685 .

Takeuti and Titani have introduced and investigated a logic they called intuitionistic fuzzy logic. This logic is characterized as the first-order Gödel logic based on the truth value set [0,1]. The logic is known to be axiomatizable, but no deduction system amenable to proof-theoretic, and hence, computational treatment, has been known. Such a system is presented here, based on previous work on hypersequent calculi for propositional Gödel logics by Avron. It is shown that the system is sound and complete, and (...) allows cut-elimination. A question by Takano regarding the eliminability of the Takeuti-Titani density rule is answered affirmatively. (shrink)

The problem of approximating a propositional calculus is to find many-valued logics which are sound for the calculus (i.e., all theorems of the calculus are tautologies) with as few tautologies as possible. This has potential applications for representing (computationally complex) logics used in AI by (computationally easy) many-valued logics. It is investigated how far this method can be carried using (1) one or (2) an infinite sequence of many-valued logics. It is shown that the optimal candidate matrices for (1) can (...) be computed from the calculus. (shrink)