It is shown that axiomatic extensions of intuitionistic propositional calculus defining univocally new connectives, including those proposed by Gabbay, are strongly complete with respect to valuations in Heyting algebras with additional operations. In all cases, the double negation of such a connective is equivalent to a formula of intuitionistic calculus. Thus, under the excluded third law it collapses to a classical formula, showing that this condition in Gabbay's definition is redundant. Moreover, such connectives can not be interpreted in all Heyting (...) algebras, unless they are already equivalent to a formula of intuitionistic calculus. These facts relativize to connectives over intermediate logics. In particular, the intermediate logic with values in the chain of length n may be "completed" conservatively by adding a single unary connective, so that the expanded system does not allow further axiomatic extensions by new connectives. (shrink)

An extensions by new axioms and rules of an algebraizable logic in the sense of Blok and Pigozzi is not necessarily algebraizable if it involves new connective symbols, or it may be algebraizable in an essentially different way than the original logic. However, extension whose axioms and rules define implicitly the new connectives are algebraizable, via the same equivalence formulas and defining equations of the original logic, by enriched algebras of its equivalente quasivariety semantics. For certain strongly algebraizable logics, all (...) connectives defined implicitly by axiomatic extensions of the logic are explicitly definable. (shrink)

El adiós a las escuelas -- El capitalismo, motor de la modernidad tardía.

Two sources of possible disagreement in bioethics may be associated with pessimism about what bioethics can achieve. First, pluralism implies that bioethics engages with interlocutors who hold divergent moral beliefs. Pessimists might believe that these disagreements significantly limit the extent to which bioethics can provide normatively robust guidance in relevant areas. Second, the interdisciplinary nature of bioethics suggests that interlocutors may hold divergent views on the nature of bioethics itself—particularly its practicality. Pessimists may suppose that interdisciplinary disagreements could frustrate the (...) goals of bioethics. In this article, I explore how wonder may alleviate the concerns of the first group of pessimists regarding problems associated with pluralism, provided that we are willing to accept some interdisciplinary frustrations. Then, I invite readers of this issue of The Journal of Medicine & Philosophy to test these intuitions by considering the role of wonder in these articles. (shrink)

In this paper we discuss how Causal Decision Theory should be modified to handle a class of problematic cases involving deterministic laws. Causal Decision Theory, as it stands, is problematically biased against your endorsing deterministic propositions (for example it tells you to deny Newtonian physics, regardless of how confident you are of its truth). Our response is that this is not a problem for Causal Decision Theory per se, but arises because of the standard method for assessing the truth of (...) certain counterfactuals. The truth of deterministic laws is `modally fragile' on the standard semantics for counterfactuals: if determinism is true and you were to do otherwise, the laws would be different. We provide two ways of avoiding this problem: 1) supplement the standard semantics for counterfactuals with impossible worlds, or 2) introduce rigid designators into the description of problematic decision situations. We argue that both of these approaches are well-motivated and can be readily incorporated into Lewisian Causal Decision Theory. (shrink)

In the absence of Woodin cardinals, fine structural inner models for mild large cardinal hypotheses admit forcing extensions where bounded forcing axioms hold and yet the reals are projectively well-ordered.

In the paper, a detailed analysis of some new logical aspects of Cantor’s diagonal proof of the uncountability of continuum is presented. For the first time, strict formal, axiomatic, and algorithmic definitions of the notions of potential and actual infinities are presented. It is shown that the actualization of infinite sets and sequences used in Cantor’s proof is a necessary, but hidden, condition of the proof. The explication of the necessary condition and its factual usage within the framework of Cantor’s (...) proof makes, Cantor’s proof invalid. It’s shown that traditional Cantor’s proof has a second necessary, but hidden as well, condition which is teleological by its nature, i.e., is not mathematical. The explication of the second necessary condition makes Cantor’s statement on the uncountability of continuum unprovable from the point of view of classical logic.One of the most dramatic facts in history of science is connected just with the notion of actual infinity and consists in the following. On the one hand, Aristotle, Berkeley, Locke, Descartes, Spinoza, Gauss, Kant, Cauchy, Kronecker, Hermite, Poincaré, Bair, Borel, Brouwer, Quine, Wittgenstein, Weyl, Luzin, and a lot of other outstanding creators of classical logic and classical mathematics, during millenniums, stated categorically and insistently warned about that the actual infinity is a self-contradictory notion and its usage in mathematics is inadmissible (e.g., according to Poincare, “There is no actual infinity. - Cantorians forgot that and fell into contradictions. Later generations will regard Mengenlehre (set theory) as a disease from which one has recovered”). On the other hand, a lot of outstanding scientists of the XX c.c., such as Hilbert, Church, Turing, Gödel, etc., and modern axiomatic set theory as a whole ignored this (intuitive though) opinion of genii and accepted Cantor’s “transfinite paradise”, based on the actual infinity. In the paper some logical, philosophical, and psychological aspects of this historical “favorable opposition” are analyzed, and the fact that the scientific intuition of genii has won the historical battle against the mytho-’logic’ of Cantor’s transfinite ‘paradise’ is explained and logically justified. (shrink)

In the paper, a detailed analysis of some new logical aspects of Cantor’s diagonal proof of the uncountability of continuum is presented. For the first time, strict formal, axiomatic, and algorithmic definitions of the notions of potential and actual infinities are presented. It is shown that the actualization of infinite sets and sequences used in Cantor’s proof is a necessary, but hidden, condition of the proof. The explication of the necessary condition and its factual usage within the framework of Cantor’s (...) proof makes, Cantor’s proof invalid. It’s shown that traditional Cantor’s proof has a second necessary, but hidden as well, condition which is teleological by its nature, i.e., is not mathematical. The explication of the second necessary condition makes Cantor’s statement on the uncountability of continuum unprovable from the point of view of classical logic.One of the most dramatic facts in history of science is connected just with the notion of actual infinity and consists in the following. On the one hand, Aristotle, Berkeley, Locke, Descartes, Spinoza, Gauss, Kant, Cauchy, Kronecker, Hermite, Poincaré, Bair, Borel, Brouwer, Quine, Wittgenstein, Weyl, Luzin, and a lot of other outstanding creators of classical logic and classical mathematics, during millenniums, stated categorically and insistently warned about that the actual infinity is a self-contradictory notion and its usage in mathematics is inadmissible (e.g., according to Poincare, “There is no actual infinity. - Cantorians forgot that and fell into contradictions. Later generations will regard Mengenlehre (set theory) as a disease from which one has recovered”). On the other hand, a lot of outstanding scientists of the XX c.c., such as Hilbert, Church, Turing, Gödel, etc., and modern axiomatic set theory as a whole ignored this (intuitive though) opinion of genii and accepted Cantor’s “transfinite paradise”, based on the actual infinity. In the paper some logical, philosophical, and psychological aspects of this historical “favorable opposition” are analyzed, and the fact that the scientific intuition of genii has won the historical battle against the mytho-’logic’ of Cantor’s transfinite ‘paradise’ is explained and logically justified. (shrink)

Mental causation is notoriously threatened by the causal exclusion argument. A prominent strategy to save mental causation from causal exclusion consists in subscribing to an interventionist account of causation. This move has, however, recently been challenged by several authors. In this paper, we do two things: We (i) develop what we consider to be the strongest version of the interventionist causal exclusion argument currently on the market and (ii) propose a new way how it can in principle be overcome. In (...) particular, we propose to replace strict supervenience in the assumption that the mental supervenes on the physical by probabilistic supervenience and show how this move has the potential to license the inference to mental causation. Finally, we argue that probabilistic supervenience captures some of the most important intuitions that strict supervenience captures and discuss possible objections to weakening strict supervenience in the way we suggest. (shrink)

A new speculative ontology of aesthetics. In Aesthesis and Perceptronium, Alexander Wilson presents a theory of materialist and posthumanist aesthetics founded on an original speculative ontology that addresses the interconnections of experience, cognition, organism, and matter. Entering the active fields of contemporary thought known as the new materialisms and realisms, Wilson argues for a rigorous redefining of the criteria that allow us to discriminate between those materials and objects where aesthesis (perception, cognition) takes place and those where it doesn't. (...) Aesthesis and Perceptronium negotiates between indiscriminately pluralist views that attribute mentation to all things and eliminative views that deny the existence of mentation even in humans. By recasting aesthetic questions within the framework of "epistemaesthetics," which considers cognition and aesthetics as belonging to a single category that can neither be fully disentangled nor fully reduced to either of its terms, Wilson forges a theory of nonhuman experience that avoids this untenable dilemma. Through a novel consideration of the evolutionary origins of cognition and its extension in technological developments, the investigation culminates in a rigorous reevaluation of the status of matter, information, computation, causality, and time in terms of their logical and causal engagement with the activities of human and nonhuman agents. (shrink)

In this paper, we present a prenex form theorem for a version of Independence Friendly logic, a logic with imperfect information. Lifting classical results to such logics turns out not to be straightforward, because independence conditions make the formulas sensitive to signalling phenomena. In particular, nested quantification over the same variable is shown to cause problems. For instance, renaming of bound variables may change the interpretations of a formula, there are only restricted quantifier extraction theorems, and slashed connectives cannot be (...) so easily removed. Thus we correct some claims from Hintikka [8], Caicedo & Krynicki [3] and Hodges [11]. We refine definitions, in particular the notion of equivalence, and sharpen preconditions, allowing us to restore those claims, including the prenex form theorem of Caicedo & Krynicki [3], and, as a side result, we obtain an application to Skolem forms of classical formulas. It is a known fact that a complete calculus for IF-logic is impossible, but with our results we establish several quantifier rules that form a partial calculus of equivalence for a general version of IF-logic reflecting general properties of information flow in games. (shrink)

It is shown that axiomatic extensions of intuitionistic propositional calculus defining univocally new connectives, including those proposed by Gabbay, are strongly complete with respect to valuations in Heyting algebras with additional operations. In all cases, the double negation of such a connective is equivalent to a formula of intuitionistic calculus. Thus, under the excluded third law it collapses to a classical formula, showing that this condition in Gabbay's definition is redundant. Moreover, such connectives can not be interpreted in all Heyting (...) algebras, unless they are already equivalent to a formula of intuitionistic calculus. These facts relativize to connectives over intermediate logics. In particular, the intermediate logic with values in the chain of length n may be "completed" conservatively by adding a single unary connective, so that the expanded system does not allow further axiomatic extensions by new connectives. (shrink)

We prove strong completeness of the □-version and the ◊-version of a Gödel modal logic based on Kripke models where propositions at each world and the accessibility relation are both infinitely valued in the standard Gödel algebra [0,1]. Some asymmetries are revealed: validity in the first logic is reducible to the class of frames having two-valued accessibility relation and this logic does not enjoy the finite model property, while validity in the second logic requires truly fuzzy accessibility relations and this (...) logic has the finite model property. Analogues of the classical modal systems D, T, S4 and S5 are considered also, and the completeness results are extended to languages enriched with a discrete well ordered set of truth constants. (shrink)

We introduce and consider the inner-model reflection principle, which asserts that whenever a statement \varphi(a) in the first-order language of set theory is true in the set-theoretic universe V, then it is also true in a proper inner model W \subset A. A stronger principle, the ground-model reflection principle, asserts that any such \varphi(a) true in V is also true in some non-trivial ground model of the universe with respect to set forcing. These principles each express a form of width (...) reflection in contrast to the usual height reflection of the Lévy–Montague reflection theorem. They are each equiconsistent with ZFC and indeed \Pi_2-conservative over ZFC, being forceable by class forcing while preserving any desired rank-initial segment of the universe. Furthermore, the inner-model reflection principle is a consequence of the existence of sufficient large cardinals, and lightface formulations of the reflection principles follow from the maximality principle MP and from the inner-model hypothesis IMH. We also consider some questions concerning the expressibility of the principles. (shrink)

We study a class of [0,1][0,1]-valued logics. The main result of the paper is a maximality theorem that characterizes these logics in terms of a model-theoretic property, namely, an extension of the omitting types theorem to uncountable languages.

Lindström’s theorem obviously fails as a characterization of first-order logic without identity ( $\mathcal {L}_{\omega \omega }^{-} $ ). In this note, we provide a fix: we show that $\mathcal {L}_{\omega \omega }^{-} $ is a maximal abstract logic satisfying a weak form of the isomorphism property (suitable for identity-free languages and studied in [11]), the Löwenheim–Skolem property, and compactness. Furthermore, we show that compactness can be replaced by being recursively enumerable for validity under certain conditions. In the proofs, we (...) use a form of strong upwards Löwenheim–Skolem theorem not available in the framework with identity. (shrink)

An extensions by new axioms and rules of an algebraizable logic in the sense of Blok and Pigozzi is not necessarily algebraizable if it involves new connective symbols, or it may be algebraizable in an essentially different way than the original logic. However, extension whose axioms and rules define implicitly the new connectives are algebraizable, via the same equivalence formulas and defining equations of the original logic, by enriched algebras of its equivalente quasivariety semantics. For certain strongly algebraizable logics, all (...) connectives defined implicitly by axiomatic extensions of the logic are explicitly definable. (shrink)

For a novice this book is a mathematically-oriented introduction to modal logic, the discipline within mathematical logic studying mathematical models of reasoning which involve various kinds of modal operators. It starts with very fundamental concepts and gradually proceeds to the front line of current research, introducing in full details the modern semantic and algebraic apparatus and covering practically all classical results in the field. It contains both numerous exercises and open problems, and presupposes only minimal knowledge in mathematics. A specialist (...) can use the book as a source of references. Results and methods of many directions in propositional modal logic, from completeness and duality to algorithmic problems, are collected and systematically presented in one volume. (shrink)

Este trabajo se encuadra dentro de una nueva visión de la lógica de Leibniz, la cual pretende mostrar que sus escritos fueron ricos no solamente en proyectos ambiciosos sino también en desarrollos lógico-matematicos concretos. Se demuestra que su “Caracteristica Numerica” que asigna pares de números a las proposiciones categóricas es una semántiea para la cual la silogística aristotélica es correcta y completa, y que el sistema algebraico presentado en Fundamentos de un Cálculo Lógico es una lógica algebraica similar a la (...) de Boole.This work is a contribution to a new view of Leibniz’s logic, pretending to show that his writings were not only rich in projects, but also in concrete logico-mathematical developments. We prove that his “Numerical Characteristic” assigning pairs of numbers to terms of categorical propositions, is a complete and correct semantics for aristotelian syllogistic, and the algebraic system presented in Fundamentals of Logical Calculus is essentially a complete version of boolean algebraic logic. (shrink)

This volume contains the proceedings of the Logic at Harvard conference in honor of W. Hugh Woodin's 60th birthday, held March 27–29, 2015, at Harvard University. It presents a collection of papers related to the work of Woodin, who has been one of the leading figures in set theory since the early 1980s. The topics cover many of the areas central to Woodin's work, including large cardinals, determinacy, descriptive set theory and the continuum problem, as well as connections between set (...) theory and Banach spaces, recursion theory, and philosophy, each reflecting a period of Woodin's career. Other topics covered are forcing axioms, inner model theory, the partition calculus, and the theory of ultrafilters. This volume should make a suitable introduction to Woodin's work and the concerns which motivate it. The papers should be of interest to graduate students and researchers in both mathematics and philosophy of mathematics, particularly in set theory, foundations and related areas. (shrink)

"Contains a balanced account of recent advances in set theory, model theory, algebraic logic, and proof theory, originally presented at the Tenth Latin American Symposium on Mathematical Logic held in Bogata, Columbia. Traces new interactions among logic, mathematics, and computer science. Features original research from over 30 well-known experts worldwide.".

If there is no inner model with ω many strong cardinals, then there is a set forcing extension of the universe with a projective well-ordering of the reals.

If the bounded proper forcing axiom BPFA holds and ω 1 = ${\mathrm{\omega }}_{1}^{\mathrm{L}}$ , then there is a lightface ${\mathrm{\Sigma }}_{3}^{1}$ well-ordering of the reals. The argument combines a well-ordering due to Caicedo-Veličković with an absoluteness result for models of MA in the spirit of "David's trick." We also present a general coding scheme that allows us to show that BPFA is equiconsistent with R being lightface ${\mathrm{\Sigma }}_{4}^{1}$ , for many "consistently locally certified" relations R on $\mathrm{\mathbb{R}}$ (...) . This is accomplished through a use of David's trick and a coding through the ∑ 2 stable ordinals of L. (shrink)

A supplemental document for "Metalinguistic Gradability".

Multiple states are at risk of becoming uninhabitable due to climate change, forcing their populations to flee. While the 1951 Refugee Convention provides the gold standard of international protection, it is only applied to a limited subset of people fleeing their countries, those who suffer persecution, which most people fleeing climate change cannot establish. While many journalists and non-lawyers freely use the term “climate refugees,” governments, and courts, as well as UNHCR and many refugee experts, have excluded most climate refugees (...) from the Convention as a matter of legal interpretation. In our 2015 paper, “Unable to Return in the 1951 Refugee Convention: Stateless Refugees and Climate Change”, we sought to reopen the debate on “climate refugees” by arguing that some climate refugees qualify under the 1951 Convention as it is currently written (even if they are not persecuted): those who are stateless and are unable to return to their country of origin because climate change has rendered it uninhabitable. Our interpretation, however, has been rejected by Goodwin-Gill and McAdam (2021) and by Foster and Lambert (2019), which explicitly responds to our paper. Here, we address and respond to their arguments, and develop a new supplementary one, drawing on the principle of systemic integration, as enshrined in Article 31(3)(c) of the Vienna Convention on the Law of Treaties. (shrink)

We generalize a theorem of Mundici relating compactness of a regular logic L to a strong form of normality of the associated spaces of models. Moreover, it is shown that compactness is in fact equivalent to ordinary normality of the model spaces when L has uniform reduction for infinite disjoint sums of structures. Some applications follow. For example, a countably generated logic is countably compact if and only if every clopen class in the model spaces is elementary. The model spaces (...) of L are not normal for vocabularies of uncountable power ωα. It also follows that first-order logic is the only finite-dependence logic having normal model spaces and satisfying at the same time the downward Löwenheim-Skolem theorem and uniform reduction for pairs. (shrink)

Kant and Fichte developed the concept of a worldview as a way of reflecting on experience as a whole. But what does it mean to form a worldview? And what role did it play in the German Idealist tradition? This paper seeks to answer these questions through a detailed analysis of the form of a philosophical worldview and its historical portent, both of which remain unexplored in the literature. The dearth of attention is partially to blame on Kant’s desultory development (...) of it, as well as its place in Fichte’s understudied lectures on religion. In this paper, I first reconstruct Kant’s conception as the starting point and then trace it to Fichte who went on to evolve it further. Fichte endorses the basic conceptual shape pioneered by Kant, namely, a reflective process of positing an idea and then checking the coherence of necessary judgments relative to it. However, Fichte came to realize that its philosophical function needed expanding. Beyond recognizing the possibility for alternative worldviews, Fichte further fleshed out how worldview creation could lead to human flourishing. The common feature between both thinkers is that the formation of a worldview aims to turn philosophy into a life-orienting exercise. (shrink)

Kant’s accounts of the Highest Good and the moral argument for God and immortality are central features of his philosophy. But both involve lingering puzzles. In this entry, we first explore what the Highest Good is for Kant and the role it plays in a complete account of ethical life. We then focus on whether the Highest Good involves individuals only, or whether it also connects with Kant’s doctrines about the moral progress of the species. In conclusion, we look into (...) three ways of articulating the moral argument for God and immorality that take our commitment to the Highest Good as their point of departure. (shrink)

Los debates sobre el conocimiento, la realidad y la verdad han estado en el centro de la discusión filosófica desde hace décadas. El advenimiento de la Teoría Evolucionista del Conocimiento le ha revestido, no solo de hipótesis interesantes sobre los procesos que subyacen a las capacidades cognitivas en la tarea de conocer el mundo, sino que ha traído consigo nuevos problemas. En este artículo se intenta ofrecer una perspectiva naturalizada del problema del conocimiento, adentrándonos en los debates suscitados desde el (...) realismo y los conceptos de verdad y error a la hora de determinar si el éxito biológico está íntimamente relacionado o no con ambos conceptos, no solo en la especie humana sino también en otras especies animales. (shrink)

The familiar Vendler-Kenny scheme of verb-types, viz., performances (further differentiated by Vedler into accomplishments and achievements), activities, and states, is too narrow in two important respects. First, it is narrow linguistically. It fails to take into account the phenomenon of verb aspect. The trichotomy is not one of verbs as lexical types but of predications. Second, the trichotomy is narrow ontologically. It is a specification in the context of human agency of the more fundamental, topic-neutral trichotomy, event-process-state.The central component in (...) this ontological trichotomy, event, can be sharply differentiated from its two flanking components by adapting a suggestion by Geoffrey N. Leech and others that the contrast between perfective and imperfective aspect in verbs corresponds to the count/mass distinction in the domain of nouns. With the help of two distinctions, of cardinal count adverbials versus frequency adverbials, and of occurrence versus associated occasion, two interrelated criteria for event predication are developed. Accordingly, Mary capsized the boat is an event predication because (a) it is equivalent to There was at least one capsizing of the boat by Mary, or (b) because it admits cardinal count adverbials, e.g., at least once, twice, three times. Ontologically speaking, events are defined as those occurrences that are inherently countable. (shrink)

Desde su descolonización en los años sesenta, África ha sido entendida en el imaginario global como un lugar de conflictos armados, inestabilidad política y pobreza. Sin embargo, durante las últimas décadas, el continente ha atravesado un importante proceso de estabilización, democratización y pacificación. Desde el liderazgo de Mandela en África en la década de 1990 hasta la creación y consolidación de la Unión Africana (UA) desde 2002, los esfuerzos pacificadores han transformado radicalmente el continente. En este proceso han participado numerosos (...) actores internacionales, continentales y regionales como las Naciones Unidas (ONU), la UA y organizaciones regionales como la Comunidad para el Desarrollo del África Meridional (SADC), que, en conjunto, han implementado diferentes enfoques para la consolidación de la paz en el continente. Uno de ellos es la puesta en marcha de una activa iniciativa de "Diplomacia Preventiva" destinada a hacer frente a las tensiones antes de que se conviertan en conflictos armados. Algunos de los ejemplos más importantes son la disputa entre Malawi y Tanzania por la demarcación de las fronteras nacionales en el lago Malawi y la participación continental en la resolución de las crisis políticas de Lesoto y Gambia. Este capítulo destaca los esfuerzos para prevenir los conflictos en África, a nivel estatal y desde las organizaciones regionales. También se analiza la forma en que África se ha convertido en un punto de referencia en las iniciativas internacionales de diplomacia preventiva, al tiempo que se asumen las carencias y dificultades a las que todavía se enfrenta el aparato de consolidación de la paz del continente. (shrink)

Analyzes the poem "On Nature" by Parmenides, arguing that is actually a philosophical argument disguised as Homer-like mythological journey. Original.

It is shown that Friedman's problem, whether there exists a proper extension of first order logic satisfying the compactness and interpolation theorems, has extremely simple positive solutions if one considers extensions by generalized (finitary) propositional connectives. This does not solve, however, the problem of whether such extensions exist which are also closed under relativization of formulas.

There is an underlying assumption in the social sciences that consciousness and social life are ultimately classical physical/material phenomena. In this ground-breaking book, Alexander Wendt challenges this assumption by proposing that consciousness is, in fact, a macroscopic quantum mechanical phenomenon. In the first half of the book, Wendt justifies the insertion of quantum theory into social scientific debates, introduces social scientists to quantum theory and the philosophical controversy about its interpretation, and then defends the quantum consciousness hypothesis against the (...) orthodox, classical approach to the mind-body problem. In the second half, he develops the implications of this metaphysical perspective for the nature of language and the agent-structure problem in social ontology. Wendt's argument is a revolutionary development which raises fundamental questions about the nature of social life and the work of those who study it. (shrink)