We group the existing variants of the familiar set-theoretical and truth-theoretical paradoxes into two classes: connective paradoxes, which can in principle be ascribed to the presence of a contracting connective of some sort, and structural paradoxes, where at most the faulty use of a structural inference rule can possibly be blamed. We impute the former to an equivocation over the meaning of logical constants, and the latter to an equivocation over the notion of consequence. Both equivocation sources are tightly related, (...) and can be cleared up by adopting a particular substructural logic in place of classical logic. We then argue that our perspective can be justified via an informational semantics of contraction-free substructural logics. (shrink)

Why are mistaken beliefs about Covid-19 so prevalent? Political identity, education and other demographic variables explain only a part of individual differences in the susceptibility to Covid-19 misinformation. This paper focuses on another explanation: epistemic vice. Epistemic vices are character traits that interfere with acquiring, maintaining, and transmitting knowledge. If the basic assumption of vice epistemology is right, then people with epistemic vices such as indifference to the truth or rigidity in their belief structures will tend to be more susceptible (...) to believing Covid-19 misinformation. We carried out an observational study (US sample, n = 998) in which we measured the level of epistemic vice of participants using a novel Epistemic Vice Scale. We also asked participants questions eliciting the extent to which they subscribe to myths and misinformation about Covid-19. We find overwhelming evidence to the effect that epistemic vice is associated with susceptibility to Covid-19 misinformation. In fact, the association turns out to be stronger than with political identity, educational attainment, scores on the Cognitive Reflection Test, personality, dogmatism, and need for closure. We conclude that this offers evidence in favor of the empirical presuppositions of vice epistemology. (shrink)

This paper focuses on the role of punishment as a critical social mechanism for cheating prevention in MMORPGs. The role of punishment is empirically investigated in a case study of the MMORPG Tibia and by focusing on the use of bots to cheat. We describe the failure of punishment in Tibia, which is perceived by players as one of the elements facilitating the proliferation of bots. In this process some players act as a moral enterprising group contributing to the reform (...) of the game rules and in particular to the reform of the Tibia punishment system by the game company. In the conclusion we consider the ethical issues raised by our findings and we propose some general reflections on the role of punishment and social mechanisms for the governance of online worlds more generally. (shrink)

We prove that the category of Nachbin’s compact ordered spaces and order-preserving continuous maps between them is dually equivalent to a variety of algebras, with operations of at most countable arity. Furthermore, we observe that the countable bound on the arity is the best possible: the category of compact ordered spaces is not dually equivalent to any variety of finitary algebras. Indeed, the following stronger results hold: the category of compact ordered spaces is not dually equivalent to any finitely accessible (...) category, any first-order definable class of structures, and any class of finitary algebras closed under products and subalgebras. An explicit equational axiomatisation of the dual of the category of compact ordered spaces is obtained; in fact, we provide a finite one, meaning that our description uses only finitely many function symbols and finitely many equational axioms. In preparation for the latter result, we establish a generalisation of a celebrated theorem by Mundici: our result—whose proof is independent of Mundici’s theorem—asserts that the category of unital commutative distributive lattice-ordered monoids is equivalent to the category of what we call MV-monoidal algebras.Abstract taken directly from the thesis.E-mail: marco[email protected]: https://air.unimi.it/retrieve/handle/2434/812809/1698986/phd_unimi_R11882.pdf. (shrink)

Es innegable que la noción de epoché fue crucial para el surgimiento y el posterior desarrollo de la tradición fenomenológica. Si bien la resignificación que Husserl hace de ésta es sumamente original, él mismo se detiene a reconocer en la filosofía antigua el mérito de haber encontrado el camino idóneo para acceder a la subjetividad trascendental. En el siguiente trabajo buscaré, por un lado, definir la epoché tal como se origina en el pensamiento de los sofistas para luego pasar a (...) analizar el modo en el que Husserl logra reversionar dicha noción hasta convertirla en el método predilecto que nos permite arribar a la esfera trascendental. Por otro lado, continuaré rastreando la evolución de la epoché para llegar a su abandono en la filosofía de Sartre. En relación con esto último, me interesa preguntarme si el existencialismo reniega de la suspensión del juicio por considerarla inapropiada o si, más bien, se trata de una supresión parcial del método fenomenológico. Me propongo defender esta segunda tesis, alegando que, en realidad, la epoché no es una noción que esté totalmente ausente en la filosofía de Sartre sino que se mantiene vigente en términos de angustia existencial. (shrink)

Portuguese translation of Aristotle’s _Prophecy in Sleep_, preceded by a short presentation of the text and accompanied by explanatory notes.

Here, we discuss historical, philosophical and technical problems associated with relating logic and relating semantics. To do so, we proceed in three steps. First, Section 1 is devoted to providing an introduction to both relating logic and relating semantics. Second, we address the history of relating semantics and some of the main research directions and their philosophical applications. Third, we discuss some technical problems related to relating semantics, particularly whether the direct incorporation of the relation into the language of relating (...) logic is needed. The starting point for our considerations presented here is the 1st Workshop On Relating Logic and the selected papers for this issue. (shrink)

The following is an attempt to read Anselm’s treatise De veritate in accordance with its immanent intention by considering the question: to what extent and in which sense does it, in unfolding the concept of truth, more concretely determine the concept of God—and accordingly also the concept of man and his relationship to God? The question of whether and to what extent Anselm argues sola ratione will not be raised, but instead in what way his ratio is capable of developing (...) out of the data of belief a conceptuality that is binding for the intellectus credens. (shrink)

The aim of the present book is to give a comprehensive account of the ‘state of the art’ of substructural logics, focusing both on their proof theory and on their semantics (both algebraic and relational. It is for graduate students in either philosophy, mathematics, theoretical computer science or theoretical linguistics as well as specialists and researchers.

In this paper we introduce a new natural deduction system for the logic of lattices, and a number of extensions of lattice logic with different negation connectives. We provide the class of natural deduction proofs with both a standard inductive definition and a global graph-theoretical criterion for correctness, and we show how normalisation in this system corresponds to cut elimination in the sequent calculus for lattice logic. This natural deduction system is inspired both by Shoesmith and Smiley's multiple conclusion systems (...) for classical logic and Girard's proofnets for linear logic. (shrink)

Integrity is often conceived as a moral virtue that pertains to the coherence between one’s moral convictions and actions, as well as consistency in convictions over time. By contrast, I argue that integrity is primarily an epistemic virtue. To act with integrity, an individual or organisation must engage in responsible inquiry; that is, the collection, processing, sharing, and storage of information in ways that promote truth. Organisational structures such as division of labour and hierarchy present challenges to responsible inquiry, thereby (...) making epistemic integrity in organisations inherently vulnerable and increasing the risk of unintentional unethical behaviour. This epistemic perspective on organisational integrity emphasises the importance of developing virtuous epistemic infrastructure and an ethical epistemic culture. By aligning their beliefs with facts, organisations can also improve moral behaviour and reduce the risk of culpable ignorance. (shrink)

Il problema del mondo è stato l'interesse teoretico di tutta la vita di Patočka. Questo tema si collega alla domanda classica della filosofia occidentale su che cos'è il reale. Anche la fenomenologia ha indagato questa questione riconoscendo nel mondo un costante presupposto e, insieme, un problema aperto. La presente indagine espone ed analizza il percorso argomentativo del filosofo ceco su questo problema filosofico. In che modo il mondo si dà a noi e qual è il fondamento del suo mostrarsi? Cosa (...) diventa il soggetto, destinatario dell'apparire, se è un momento del manifestarsi del mondo? Il metodo husserliano ha seguito l'analisi della coscienza intenzionale, Patočka, invece, ha parlato di una desoggettivazione dell'apparire e si è mosso a un livello più originario per tentare di cogliere l'emergenza del fenomenale. Il mondo naturale pre-teorico diventa, in questo modo, soltanto una via allo svelamento di una condizione più originaria: la concezione fenomenologico-trascendentale del mondo. Riformulando il concetto di mondo come totalità, alcuni concetti, come quelli di epoché e di apparizione, subiscono una torsione. Il filosofo ceco ha spinto la riflessione filosofica più avanti ed occupa oramai un posto originale nel movimento fenomenologico come lo dimostrano numerose pubblicazioni internazionali nel contesto non più soltanto europeo. Lo spazio aperto tra il senso profondo delle formulazioni di Husserl e il loro ripensamento ci insegna ad apprezzare i risultati dell'indagine fenomenologica nel loro giusto valore, non come verità assolute ma tappe di un percorso; e insieme è di stimolo a proseguire queste aperture, per lo più ancora inesplorate nelle loro conseguenze. (shrink)

Paraconsistent Weak Kleene Logic is the 3-valued propositional logic defined on the weak Kleene tables and with two designated values. Most of the existing proof systems for PWK are characterised by the presence of linguistic restrictions on some of their rules. This feature can be seen as a shortcoming. We provide a cut-free calculus for PWK that is devoid of such provisos. Moreover, we introduce a Priest-style tableaux calculus for PWK.

O ficcionalismo, geralmente classificado como um tipo de nominalismo, apresenta como perspectiva precípua a tese de que os entes matemáticos são ficções. Para o ficcionalista, o discurso matemático é desprovido de conteúdo. Hartry Field, que é o principal defensor dessa concepção ontológica da matemática, contesta, em Science Without Numbers, a utilização de entes matemáticos na redação de teorias da física, alegando que a defesa mais plausível do realismo ontológico matemático é o argumento da indispensabilidade de Quine-Putnam. O ficcionalismo defendido por (...) Field nos permite, de acordo com Shapiro, classificá-lo no grupo filosofia-primeiro, ou seja, entre os filósofos que defendem que a filosofia deve ser responsável por legislar a respeito da prática matemática. Dessa forma, podemos considerar Field um revisionista epistemológico. Como se sabe, a dependência da ciência moderna em relação ao discurso matemático coloca a tese ficcionalista em xeque. Ainda assim, se partirmos dos pressupostos filosóficos da vertente formalista da filosofia da matemática, que concebe a matemática como constituída de um conjunto de regras sem significado que podem ser manipuladas de maneira puramente sintática, poderemos traçar importantes analogias entre matemática e ficção, tal como também entre metamatemática e metaficção. Para um formalista simpático à tese ficcionalista, o estatuto ontológico da matemática é semelhante ao das regras de um jogo de xadrez. (shrink)

Proof-theoretic semantics is an alternative to model-theoretic semantics. It aims at explaining the meaning of the logical constants in terms of the inference rules that govern their behaviour in proofs. We argue that this must be construed as the task of explaining these meanings relative to a logic, i.e., to a consequence relation. Alas, there is no agreed set of properties that a relation must have in order to qualify as a consequence relation. Moreover, the association of a consequence relation (...) to a logical calculus is not as straightforward as it may seem. We show that these facts are problematic for the proof-theoretic project but the problems can be solved. Our thesis is that the consequence relation relevant for proof-theoretic semantics is the one given by the sequent-to-sequent derivability relation in Gentzen systems. (shrink)

Dave Ripley has recently argued against the plausibility of multiset consequence relations and of contraction-free approaches to paradox. For Ripley, who endorses a nontransitive theory, the best arguments that buttress transitivity also push for contraction—whence it is wiser for the substructural logician to go nontransitive from the start. One of Ripley’s allegations is especially insidious, since it assumes the form of a trivialisation result: it is shown that if a multiset consequence relation can be associated to a closure operator in (...) the expected way, then it necessarily contracts. We counter Ripley’s objection by presenting an approach to multiset consequence that escapes this trap. This approach is multiple-conclusioned in a heterodox way, for multiple succedents are given a conjunctive, rather than a disjunctive reading. Finally, we address a further objection by French and Ripley to the effect that the informational interpretation of sequents in linear logic does not motivate cut. (shrink)

The strict-tolerant approach to paradox promises to erect theories of naïve truth and tolerant vagueness on the firm bedrock of classical logic. We assess the extent to which this claim is founded. Building on some results by Girard we show that the usual proof-theoretic formulation of propositional ST in terms of the classical sequent calculus without primitive Cut is incomplete with respect to ST-valid metainferences, and exhibit a complete calculus for the same class of metainferences. We also argue that the (...) latter calculus, far from coinciding with classical logic, is a close kin of Priest’s LP. (shrink)

The logic DAI of demodalised analytic implication has been introduced by J.M. Dunn as a variation on a time-honoured logical system by C.I. Lewis’ student W.T. Parry. The main tenet underlying this logic is that no implication can be valid unless its consequent is “analytically contained” in its antecedent. DAI has been investigated both proof-theoretically and model-theoretically, but no study so far has focussed on DAI from the viewpoint of abstract algebraic logic. We provide several different algebraic semantics for DAI, (...) showing their equivalence with the known semantics by Dunn and Epstein. We also show that DAI is algebraisable and we identify its equivalent quasivariety semantics. This class turns out to be a linguistic and axiomatic expansion of involutive bisemilattices, a subquasivariety of which forms the algebraic counterpart of Paraconsistent Weak Kleene logic. This fact sheds further light on the relationship between containment logics and logics of nonsense. (shrink)

The aim of this article is to discuss pure variable inclusion logics, that is, logical systems where valid entailments require that the propositional variables occurring in the conclusion are included among those appearing in the premises, or vice versa. We study the subsystems of Classical Logic satisfying these requirements and assess the extent to which it is possible to characterise them by means of a single logical matrix. In addition, we semantically describe both of these companions to Classical Logic in (...) terms of appropriate matrix bundles and as semilattice-based logics, showing that the notion of consequence in these logics can be interpreted in terms of truth (or non-falsity) and meaningfulness (or meaninglessness) preservation. Finally, we use Płonka sums of matrices to investigate the pure variable inclusion companions of an arbitrary finitary logic. -/- . (shrink)

I discuss paradoxes of implication in the setting of a proof-conditional theory of meaning for logical constants. I argue that a proper logic of implication should be not only relevant, but also constructive and nonmonotonic. This leads me to select as a plausible candidate LL, a fragment of linear logic that differs from R in that it rejects both contraction and distribution.

According to the extended cognition thesis, an agent’s cognitive system can sometimes include extracerebral components amongst its physical constituents. Here, we show that such a view of cognition has an unjustifiably anthropocentric focus, for it tends to depict cognitive extensions as a human-only affair. In contrast, we will argue that if human cognition extends, then the cognition of many non-human animals extends too, for many non-human animals rely on the same cognition-extending strategies humans rely on. To substantiate this claim, we (...) will proceed as follows. First (Sect. 1), we will introduce the extended cognition thesis, exposing its anthropocentric bias. Then, we will show that humans and many non-human animals rely on the same cognition-extending strategies. To do so, we will discuss a variety of case studies, including “intrabodily” cognitive extensions such as the spinal cord (Sect. 2), the widespread reliance on epistemic actions to solve cognitive tasks (Sect. 3) and cases of animal cognitive offloading (Sect. 4). We’ll then allay some worries our claim might raise (Sect. 5) to then conclude the paper (Sect. 6). (shrink)

A view that emancipates free will by means of quantum indeterminism is frequently rejected based on arguments pointing out its incompatibility with what we know about quantum physics. However, if one carefully examines what classical physical causal determinism and quantum indeterminism are according to physics, it becomes clear what they really imply–and, especially, what they do not imply–for agent-causation theories. Here, we will make necessary conceptual clarifications on some aspects of physical determinism and indeterminism, review some of the major objections (...) against libertarian conjectures, and show that there is no conceptual incompatibility preventing us from taking a ‘quantum-libertarian’ approach to the problem of free will. In particular, we will illustrate the possible role of self-causation (causa sui) as a potential solution to otherwise apparently incompatible or even paradoxical statements concerning free will and quantum indeterminism. (shrink)

In a famous and controversial paper, B. H. Slater has argued against the possibility of paraconsistent logics. Our reply is centred on the distinction between two aspects of the meaning of a logical constant *c* in a given logic: its operational meaning, given by the operational rules for *c* in a cut-free sequent calculus for the logic at issue, and its global meaning, specified by the sequents containing *c* which can be proved in the same calculus. Subsequently, we use the (...) same strategy to counter Quine's meaning variance argument against deviant logics. In a nutshell, we claim that genuine rivalry between (similar) logics *L* and *L'* is possible whenever each constant in *L* has the same operational meaning as its counterpart in *L'* although differences in global meaning arise in at least one case. (shrink)

We introduce a generalization of MV algebras motivated by the investigations into the structure of quantum logical gates. After laying down the foundations of the structure theory for such quasi-MV algebras, we show that every quasi-MV algebra is embeddable into the direct product of an MV algebra and a “flat” quasi-MV algebra, and prove a completeness result w.r.t. a standard quasi-MV algebra over the complex numbers.