Walter Reese-Schäfer, Karl-Otto Apel, Zur Einführung (with an Afterword by Jürgen Habermas), Junis Verlag GmbH, Hamburg 1990, 176pp. DM 17.80 -/- The author, presently a freelance writer published in the newspaper “Die Zeit” and the magazine “Stern,” pro­vides in this small book a clear and concise introduction to sources, themes and conclusions in the philosophy of Karl-Otto Apel. Apel, Emeritus Pro­fessor at Frank­furt, and close colleague of Habermas, characterizes his viewpoint as a “transcen­dental pragmatism” in which a Kantian concern (...) for question regarding “the conditions for the possi­bility of some­thing,” (p.10) mixes with deontological discourse-ethics, semeiotic themes from Peirce, an ap­proach to fallibilism, the demand for “final justifica­tions” (Letzt­begründung) and German her­meneutics. In view of the “den­sity and concentration” of Apel’s texts, which often have a “deterrent effect” upon those not already at home with “the phil­osophical language game,” it is the announced aim of this book to provide a work of translation and clarification of Apel’s special­ized efforts --in effect an orientation to Apel’s work. The book divides into an Introduction, 8 chapters and a summary conclusion --with Habermas’ appreciation, “A Master Builder with Hermeneutic Feeling --The Way of Philosopher Karl-Otto Apel,” bringing up the rear. There is also a bibliography of primary and secondary sources and a short table outlining highlights of Apel’s career. The “Introduction” provides a good overview of the aims of the book and gets one started on central themes. (shrink)

Motivated by H. Curry’s well-known objection and by a proposal of L. Henkin, this article introduces the positive tableaux, a form of tableau calculus without refutation based upon the idea of implicational triviality. The completeness of the method is proven, which establishes a new decision procedure for the (classical) positive propositional logic. We also introduce the concept of paratriviality in order to contribute to the question of paradoxes and limitations imposed by the behavior of classical implication.

In several essays I have argued that Berkeley maintains the same basic notion of spiritual substance throughout his life. Because that notion is not the traditional (Aristotelian, Cartesian, or Lockean) doctrine of substance, critics (e.g., John Roberts, Tom Stoneham, Talia Mae Bettcher, Margaret Atherton, Walter Ott, Marc Hight) claim that on my reading Berkeley either endorses a Humean notion of substance or has no recognizable theory of substance at all. In this essay I point out how my interpretation does (...) not assume that Berkeley adopts a bundle theory of mind, but instead redefines what it means for a simple substance to be the principle by which ideas are perceived. (shrink)

Murdoch makes some ambitious claims about love’s epistemic significance which can initially seem puzzling in the light of its heterogeneous and messy everyday manifestations. I provide an interpretation of Murdochian love such that Murdoch’s claims about its epistemic significance can be understood. I argue that Murdoch conceives of love as a virtue, and as belonging at the pinnacle of the hierarchy of the virtues, and that this makes sense of the epistemic role Murdochian love fulfills. Moreover, I suggest that there (...) is good reason to think that Murdochian love is not as far from everyday conceptions of love as it can initially appear. (shrink)

Traditionally, social entities (i.e., social properties, facts, kinds, groups, institutions, and structures) have not fallen within the purview of mainstream metaphysics. In this chapter, we consider whether the exclusion of social entities from mainstream metaphysics is philosophically warranted or if it instead rests on historical accident or bias. We examine three ways one might attempt to justify excluding social metaphysics from the domain of metaphysical inquiry and argue that each fails. Thus, we conclude that social entities are not justifiably excluded (...) from metaphysical inquiry. Finally, we ask how focusing on social entities could change the character of metaphysical inquiry. We suggest that starting from examples of social entities might lead metaphysicians to rethink the assumption that describing reality in terms of intrinsic, independent, and individualistic features is preferable to describing it in terms of relational, dependent, and non-individualistic features. (shrink)

How do we know about other minds on the basis of perception? The two most common answers to this question are that we literally perceive others’ mental states, or that we infer their mental states on the basis of perceiving something else. In this paper, I argue for a different answer. On my view, we don’t perceive mental states, and yet perceptual experiences often immediately justify mental state attributions. In a slogan: other minds are neither seen nor inferred. I argue (...) that this view offers the best explanation of our deeply equivocal intuitions about perception-based mental state attributions, and also holds substantial interest for the epistemology of perception more generally. (shrink)

When we look around us, some things look “alive,” others do not. What is it to “look alive”—to perceive animacy? Empirical work supports the view that animacy is genuinely perceptual. We should construe perception of animacy as perception of agents and behavior. This proposal explains how static and dynamic animacy cues relate, and explains how animacy perception relates to social cognition more broadly. Animacy perception draws attention to objects that are apt to be well‐understood folk psychologically, enabling us to marshal (...) our folk psychological resources efficiently. (shrink)

What’s the difference between those psychological posits that are ‘me” and those that are not? Distinguishing between these psychological kinds is important in many domains, but an account of what the distinction consists in is challenging. I argue for Psychological Constructionism: those psychological posits that correspond to the kinds within folk psychology are personal, and those that don’t, aren’t. I suggest that only constructionism can answer a fundamental challenge in characterizing the personal level – the plurality problem. The things that (...) plausibly qualify as personal are motley. Other attempts at accounting for the personal level either cannot accommodate this plurality, or cannot explain what unifies the personal. Given arguments others have given for a pluralistic conception of folk psychology, constructionism explains and predicts this plurality in a systematic and unified way, thereby solving the plurality problem. (shrink)

This article introduces and defends the “pathological complexity thesis” as a hypothesis about the evolutionary origins of minimal consciousness, or sentience, that connects the study of animal consciousness closely with work in behavioral ecology and evolutionary biology. I argue that consciousness is an adaptive solution to a design problem that led to the extinction of complex multicellular animal life following the Avalon explosion and that was subsequently solved during the Cambrian explosion. This is the economic trade-off problem of having to (...) deal with a complex body with high degrees of freedom, what I call “pathological complexity.” By modeling the explosion of this computational complexity using the resources of state-based behavioral and life history theory we will be able to provide an evolutionary bottom-up framework to make sense of subjective experience and its function in nature by paying close attention to the ecological lifestyles of different animals. (shrink)

There has been much criticism of the idea that Friston's free-energy principle can unite the life and mind sciences. Here, we argue that perhaps the greatest problem for the totalizing ambitions of its proponents is a failure to recognize the importance of evolutionary dynamics and to provide a convincing adaptive story relating free-energy minimization to organismal fitness.

This paper constitutes a radical departure from the existing philosophical literature on models, modeling-practices, and model-based science. I argue that the various entities and practices called 'models' and 'modeling-practices' are too diverse, too context-sensitive, and serve too many scientific purposes and roles, as to allow for a general philosophical analysis. From this recognition an alternative view emerges that I shall dub model anarchism.

Quilty-Dunn et al. argue that deep convolutional neural networks (DCNNs) optimized for image classification exemplify structural disanalogies to human vision. A different kind of artificial vision – found in reinforcement-learning agents navigating artificial three-dimensional environments – can be expected to be more human-like. Recent work suggests that language-like representations substantially improves these agents’ performance, lending some indirect support to the language-of-thought hypothesis (LoTH).

This article canvases the main areas of controversy: the nature of Lockean signification and his position on propositions and particles.

On a currently popular reading of Locke, an idea represents its cause, or what God intended to be its cause. Against Martha Bolton and my former self (among others), I argue that Locke cannot hold such a view, since it sins against his epistemology and theory of abstraction. I argue that Locke is committed to a resemblance theory of representation, with the result that ideas of secondary qualities are not representations.

Like their contemporary counterparts, early modern philosophers find themselves in a predicament. On one hand, there are strong reasons to deny that sensations are representations. For there seems to be nothing in the world for them to represent. On the other hand, some sensory representations seem to be required for us to experience bodies. How else could one perceive the boundaries of a body, except by means of different shadings of color? I argue that Nicolas Malebranche offers an extreme -- (...) and ultimately unworkable -- attempt to solve this riddle. Most commentators claim that Malebranche defends an adverbial theory of sensation, according to which a sensation is merely a way in which an act of sensing happens. The adverbial reading is wrong, or so I argue. Once we arrive at a more accurate reading, we shall see that his position is much more strange than is currently thought. Nevertheless, Malebranche’s view is similar to the adverbial theory in one respect, albeit it at a very high level of generality. His view thus inherits two of the main problems that afflict adverbial theories. Although Malebranche fails to solve them, his ingenious attempts to do so are instructive. (shrink)

The conditions animals experience during the early developmental stages of their lives can have critical ongoing effects on their future health, welfare, and proper development. In this paper we draw on evolutionary theory to improve our understanding of the processes of developmental programming, particularly Predictive Adaptive Responses (PAR) that serve to match offspring phenotype with predicted future environmental conditions. When these predictions fail, a mismatch occurs between offspring phenotype and the environment, which can have long-lasting health and welfare effects. Examples (...) include metabolic diseases resulting from maternal nutrition and behavioral changes from maternal stress. An understanding of these processes and their evolutionary origins will help in identifying and providing appropriate developmental conditions to optimize offspring welfare. This serves as an example of the benefits of using evolutionary thinking within veterinary science and we suggest that in the same way that evolutionary medicine has helped our understanding of human health, the implementation of evolutionary veterinary science (EvoVetSci) could be a useful way forward for research in animal health and welfare. (shrink)

In this article, I discuss what motivated reasoning research tells us about the prospects for deliberative democracy. In section I, I introduce the results of several political psychology studies examining the problematic affective and cognitive processing of political information by individuals in nondeliberative, experimental environments. This is useful because these studies are often neglected in political philosophy literature. Section II has three stages. First, I sketch how the study results from section I question the practical viability of deliberative democracy. Second, (...) I briefly present the results of three empirical studies of political deliberation that can be interpreted to counter the findings of the studies in section I. Third, I show why this is a misinterpretation and that the study results from section I mean that it is implausible that sites of political deliberation would naturally emerge from the wide public sphere and coalesce into institutionalized forms of the practice such that deliberative democracy can satisfy its raison d’être. Finally, in section III, I conclude that viable conceptions of deliberative democracy should be limited to narrower aims. (shrink)

This article aims to read feminist new materialisms (Barad), together with ‘postulated’ linguistic or cultural primacy of Queer Theory (Butler), to show how both are engaged in similar critical-ethical endeavours. The central argument is that the criticism of Barad and new materialisms misses Butler’s materialistic insights due to a narrow interpretation of Butler's alleged social-constructivist position. There is, therefore, a specific focus on where they both make similar ethical appeals. Moreover, the article relies on Adorno's negative dialectic to highlight an (...) interpretation of Barad and Butler as being part of the same dialectical movement, in which materialism and idealism fluctuate in their mutual criticisms, thus continuing the procession towards 'new knowledge' and emancipation, or freedom, through their motions back and forth. (shrink)

This paper analyzes the proposed use of combinatorial derivatives markets for event prediction, especially for catastrophic events such as terrorism, war, or political assasination. Following a presentation of the philosophical principles underlying these politico-economic tools, I examine case studies (U.S. DoD proposals) that evaluate their advantages and disadvantages in terms of both efficacy and moral considerations. I conclude that these markets are both fatally flawed due to internal conceptual contradictions and morally problematic.

This interdisciplinary paper identifies principles of an affluent country (im)migration policy that avoids: (1) the positivist inclusion/exclusion mechanism of liberalism and communitarianism; and (2) the idealism of most cosmopolitan (im)migration theories. First, I: (a) critique the failure of liberalism and communitarianism to consider (im)migration under distributive justice; and (b) present cosmopolitan (im)migration approaches as a promising alternative. This paper’s central claim is that cosmopolitan (im)migration theory can determine normative shortcomings in (im)migration policy by coupling elements of Frankfurt School methodology to (...) case studies of (im)migration regimes. Lastly, I apply this analytical procedure to recent special changes in Spanish and UK immigration law. (shrink)

This paper presents the history of the Frankfurt School’s inclusion of normative concerns in social science research programs during the period 1930-1955. After examining the relevant methodology, I present a model of how such a program could look today. I argue that such an approach is both valuable to contemporary social science programs and overlooked by current philosophers and social scientists.

Alongside the rapid global advances in neuroscientific research, neuroethics has been one of the fastest growing sub-fields within bioethics. With this rapid expansion, bioethicists struggle to kee...

Are demands for equality motivated by envy? Nietzsche, Freud, Hayek, and Nozick all thought so. Call this the Envy Objection. For egalitarians, the Envy Objection is meant to sting. Many egalitarians have tried to evade the Envy Objection.. But should egalitarians be worried about envy? In this paper, I argue that egalitarians should stop worrying and learn to love envy. I argue that the persistent unwillingness to embrace the Envy Objection is rooted in a common misunderstanding of the nature of (...) the charge, what it reveals, and what can be said in response to it. I develop what Bernard Williams might call a vindicatory genealogy of envy, thereby allowing us to see that envy, rather than undermining egalitarian intuitions, can in fact play a distinct justificatory role (when it is fitting), which undermines the Envy Objection. (shrink)

Eliminativism is a position most readily associated with the eliminative materialism of the Churchlands, denying that there are such things as propositional states. This position has created much controversy, despite the fact that intentionality has long been seen as perhaps the core problem for naturalistic philosophy. There is a more radical interpretation of eliminativism, however, denying not only mental states, such as beliefs and desires, but also intentionality (i.e., aboutness) on a global level. This position traces its contemporary origin back (...) to Quine, but has generally been assumed to undermine naturalism or, worse, to be incoherent by the majority of philosophers who maintain that there clearly are things or mental states that are about others. In a recent paper, Hutto and Satne (2015a) offer an update that tries to revive John Haugeland’s baseball analogy from his influential 1990 review paper The Intentionality All-Stars on the state of the game to argue that the failure of Neo-Cartesians, Neo- Behaviorists, and Neo-Pragmatists should urge us to make them work together to naturalize content and “win the game.” But Hutto and Satne misunderstand what the game is ultimately about. The goal of the Intentionality All-Stars is not to naturalize content against eliminativism but to defend a naturalist “thirdperson” view of the problem against first-person phenomenalists. For this goal, a naturalist defense of global content eliminativism would equally enable them to emerge victorious. Revisiting Haugeland, I will offer my own analysis of the current state of play to argue that global content eliminativism has not received sufficient attention and deserves a more prominent place in the debate than it currently occupies. (shrink)

The debate over Hypothetical Syllogism is locked in stalemate. Although putative natural language counterexamples to Hypothetical Syllogism abound, many philosophers defend Hypothetical Syllogism, arguing that the alleged counterexamples involve an illicit shift in context. The proper lesson to draw from the putative counterexamples, they argue, is that natural language conditionals are context-sensitive conditionals which obey Hypothetical Syllogism. In order to make progress on the issue, I consider and improve upon Morreau’s proof of the invalidity of Hypothetical Syllogism. The improved proof (...) relies upon the semantic claim that conditionals with antecedents irrelevant to the obtaining of an already true consequent are themselves true. Moreover, this semantic insight allows us to provide compelling counterexamples to Hypothetical Syllogism that are resistant to the usual contextualist response. (shrink)

Are living organisms--as Descartes argued--just machines? Or is the nature of life such that it can never be fully explained by mechanistic models? In this thought-provoking and controversial book, eminent geophysicist Walter M. Elsasser argues that the behavior of living organisms cannot be reduced to physico-chemical causality. Suggesting that molecular biology today is at the same point as Newtonian physics on the eve of the quantum revolution, Elsasser lays the foundation for a theoretical biology that points the way toward (...) a natural philosophy of organic life. Explicitly repudiating "vitalism" (the notion that the laws of nature need to be modified when applied to living organisms), Elsasser argues instead that the structural complexity of even a single living cell is "transcomputational"--that is, beyond the power of any imaginable system to compute. Beginning from this insight, Elsasser leads the reader through a step-by-step process that ultimately arrives at the conclusion that living and non-living matter are separated by "a no-man's land of irrationality." Trained in Germany as a physicist, Elsasser first pondered the implications of quantum mechanics for biology as early as 1951. The more closely he studied the inherent complexity of life, the more skeptical he became of the reductionist view of organisms as tiny machines. "An organism," he concluded, "is a source of causal chains which cannot be traced beyond a terminal point because they are lost in the unfathomable complexity of the organism." Like the physicist who works within the bounds of an unfathomable universe, Elsasser argues, the biologist must seek answers within a system that is no less unfathomable. (shrink)

It is common to think that clarity is an essential ingredient of good teaching, meaning, in part, that good teachers always make it as easy as possible to follow what they say. We disagree. What we argue is that there are cases in which a philosophy teacher needs to forego clarity, making strategic use of obscurity in the undergraduate classroom.

I applaud recent improvements upon previous guidelines for the assessment of pain in non-human species and the application of their framework towards decapod crustaceans. Rather than constituting a mere intermediate solution between the scientific difficulty of settling questions of animal consciousness and the need for a framework for the purposes of animal welfare legislation, I will argue that the longer lists of criteria for animal sentience should make us realize that animal sentience is a multi-dimensional phenomenon that must be studied (...) with a plethora of methods in order to assess its diversity across the tree of life. (shrink)

An indeterminate version of Henry Sidgwick’s “Dualism of Practical Reason” may offer a solution to Derek Parfit’s “Repugnant Conclusion”. Here we will outline the problem of Sidgwick’s Dualism and how to resolve it within the framework of practical reason and the problem of Parfit’s Repugnance and why it is irresoluble within the framework of pure utilitarianism. Then we will argue how Sidgwick’s Dualism, under certain formulations of indeterminacy, specifically under those Indeterminacy Views advanced by David Phillips (and others), implies a (...) resolution to the Repugnant Conclusion that is both intuitive and simple, resolving Sidgwick’s Dualism and Parfit’s Repugnance in one conceptual move. (shrink)

In recent years, bioethical discourse around the topic of ‘genetic enhancement’ has become increasingly politicized. We fear there is too much focus on the semantic question of whether we should call particular practices and emerging bio-technologies such as CRISPR ‘eugenics’, rather than the more important question of how we should view them from the perspective of ethics and policy. Here, we address the question of whether ‘eugenics’ can be defended and how proponents and critics of enhancement should engage with each (...) other. (shrink)

In this commentary we advance Jagiello et al.'s proposal by zooming in on the possible evolutionary origins of the “bifocal stance” that may have enabled a major transition in human cultural evolution, arguing that the evolution of the bifocal stance was driven by an explosion in cultural complexity arising from cooperative foraging, which led to a feedback loop between the ritual and instrumental stances.

Diminishing Marginal Utility is widely accepted as a law of human action, and therefor has become one of the primary premises of ethics, economics, and politics. In popular parlance, “diminishing returns” has entered into the cliches of common sense; in philosophical argument, it has achieved the status of an axiomatic assumption; and indeed, in terms of personal experience or folk psychology, it seems to largely hold true for goods in general over a range of consumption. However, a theory of diminishing (...) marginal utility rests on some assumptions that we ignore at our peril. The a priori and a posteriori proofs of diminishing marginal utility, as developed by the Austrian economists like Ludwig von Mises and Hermann Heinrich Gossen, should be reassessed and critiqued from their fundamental principles to illuminate the theory’s pitfalls. Once these premises and their conclusions are not taken for granted, a more comprehensive and conscientious theory of value can be proposed: Complex or Inflecting Marginal Utility. (shrink)

In this paper we present a philosophical motivation for the logics of formal inconsistency, a family of paraconsistent logics whose distinctive feature is that of having resources for expressing the notion of consistency within the object language in such a way that consistency may be logically independent of non-contradiction. We defend the view according to which logics of formal inconsistency may be interpreted as theories of logical consequence of an epistemological character. We also argue that in order to philosophically justify (...) paraconsistency there is no need to endorse dialetheism, the thesis that there are true contradictions. Furthermore, we show that mbC, a logic of formal inconsistency based on classical logic, may be enhanced in order to express the basic ideas of an intuitive interpretation of contradictions as conflicting evidence. (shrink)

Catastrophic risk raises questions that are not only of practical importance, but also of great philosophical interest, such as how to define catastrophe and what distinguishes catastrophic outcomes from non-catastrophic ones. Catastrophic risk also raises questions about how to rationally respond to such risks. How to rationally respond arguably partly depends on the severity of the uncertainty, for instance, whether quantitative probabilistic information is available, or whether only comparative likelihood information is available, or neither type of information. Finally, catastrophic risk (...) raises important ethical questions about what to do when catastrophe avoidance conflicts with equity promotion. (shrink)

How language works — its functions, mechanisms, and limitations — matters to the early moderns as much as it does to contemporary philosophers. Many of the moderns make reflection on language central to their philosophical projects, both as a tool for explaining human cognition and as a weapon to be used against competing views. Even in philosophers for whom language is less central, we can find important connections between their views on language and their other philosophical commitments.

The Principle of Ariadne, formulated in 1988 ago by Walter Carnielli and Carlos Di Prisco and later published in 1993, is an infinitary principle that is independent of the Axiom of Choice in ZF, although it can be consistently added to the remaining ZF axioms. The present paper surveys, and motivates, the foundational importance of the Principle of Ariadne and proposes the Ariadne Game, showing that the Principle of Ariadne, corresponds precisely to a winning strategy for the Ariadne Game. (...) Some relations to other alternative. set-theoretical principles are also briefly discussed. (shrink)

Are workers dominated? A recent suite of neo-republican and relational egalitarian philosophers think they are. Suppose they are right; that is, suppose that some workers are governed by an unjust and arbitrary power existing in labour relations, which persists even in the presence of the actual ability to exit. My question is this: does that give us reason to impose restrictions on firms? According to the so-called Efficiency Objection there are relevant trade-offs that need to be considered between the efficiency (...) of firms and the freedom of workers, and upon considering these trade-offs, we should reject workplace democracy. In this paper, I present a dilemma for the Efficiency Objection. I argue that either the Efficiency Objection is justified on moral grounds or non-moral grounds; if the Efficiency Objection is justified on moral grounds, then it fails because efficiency cannot be valued for its own sake (it is only instrumentally good); if the Efficiency Objection is justified on non-moral grounds, then it fails because of the respect that we owe to persons as persons; therefore, the Efficiency Objection fails. (shrink)

Two kinds of people might find this useful: first, those interested in the modern debate over ideas and representation who don’t happen to read French, or who do, but would like to have in one place the relevant excerpts, to see whether looking at the originals is worth their time. Second are teachers of modern philosophy. The back-and-forth among these figures makes for a refreshing change from the massive, often self-contained works that characterize much of the rest of such a (...) course. For example, one could easily work in chapter 3 (the high point of the debate, from my point of view) between Descartes and Berkeley. (shrink)

Imagine a world where everyone is healthy, intelligent, long living and happy. Intuitively this seems wonderful, albeit unrealistic. However, recent scientific developments in genetic engineering, namely CRISPR/Cas bring the question into public discourse, how the genetic enhancement of humans should be evaluated morally.

The concept of the Utility Monster offers an influential critique of Utilitarian theories, forcing us to consider different theoretical fixes to escape monstrous implications (Nozick, 1999, pp. 26-53; Kennard, 2015, p. 322). However, many different breeds, a whole bestiary, of Utility Monsters are identifiable, and each breed reveals something slightly different about what we find monstrous. When dissected in depth, we observe that some breeds are probably acceptable, whereas other breeds are indeed monstrous, though perhaps not for the reasons Nozick (...) thought. By breaking these taxonomies down, thus revealing strengths and weaknesses of these different breeds, we may see more clearly how the vicious versions can be dispensed with under reasonable assumptions. (shrink)

Like many others, I see Crump et al. (2022) as a milestone for improving upon previous guidelines and for extending their framework to decapod crustaceans. Their proposal would benefit from a firm evolutionary foundation by adding the comparative measurement of life-history complexity as a ninth criterion for attributing sentience to nonhuman animals.

Dorothy Edgington’s work has been at the centre of a range of ongoing debates in philosophical logic, philosophy of mind and language, metaphysics, and epistemology. This work has focused, although by no means exclusively, on the overlapping areas of conditionals, probability, and paradox. In what follows, I briefly sketch some themes from these three areas relevant to Dorothy’s work, highlighting how some of Dorothy’s work and some of the contributions of this volume fit in to these debates.

Boolean-valued models of set theory were independently introduced by Scott, Solovay and Vopěnka in 1965, offering a natural and rich alternative for describing forcing. The original method was adapted by Takeuti, Titani, Kozawa and Ozawa to lattice-valued models of set theory. After this, Löwe and Tarafder proposed a class of algebras based on a certain kind of implication which satisfy several axioms of ZF. From this class, they found a specific 3-valued model called PS3 which satisfies all the axioms of (...) ZF, and can be expanded with a paraconsistent negation *, thus obtaining a paraconsistent model of ZF. The logic (PS3 ,*) coincides (up to language) with da Costa and D'Ottaviano logic J3, a 3-valued paraconsistent logic that have been proposed independently in the literature by several authors and with different motivations such as CluNs, LFI1 and MPT. We propose in this paper a family of algebraic models of ZFC based on LPT0, another linguistic variant of J3 introduced by us in 2016. The semantics of LPT0, as well as of its first-order version QLPT0, is given by twist structures defined over Boolean agebras. From this, it is possible to adapt the standard Boolean-valued models of (classical) ZFC to twist-valued models of an expansion of ZFC by adding a paraconsistent negation. We argue that the implication operator of LPT0 is more suitable for a paraconsistent set theory than the implication of PS3, since it allows for genuinely inconsistent sets w such that [(w = w)] = 1/2 . This implication is not a 'reasonable implication' as defined by Löwe and Tarafder. This suggests that 'reasonable implication algebras' are just one way to define a paraconsistent set theory. Our twist-valued models are adapted to provide a class of twist-valued models for (PS3,*), thus generalizing Löwe and Tarafder result. It is shown that they are in fact models of ZFC (not only of ZF). (shrink)

The main objective o f this descriptive paper is to present the general notion of translation between logical systems as studied by the GTAL research group, as well as its main results, questions, problems and indagations. Logical systems here are defined in the most general sense, as sets endowed with consequence relations; translations between logical systems are characterized as maps which preserve consequence relations (that is, as continuous functions between those sets). In this sense, logics together with translations form a (...) bicomplete category of which topological spaces with topological continuous functions constitute a full subcategory. We also describe other uses of translations in providing new semantics for non-classical logics and in investigating duality between them. An important subclass of translations, the conservative translations, which strongly preserve consequence relations, is introduced and studied. Some specific new examples of translations involving modal logics, many-valued logics, para- consistent logics, intuitionistic and classical logics are also described. (shrink)

One of the most expected properties of a logical system is that it can be algebraizable, in the sense that an algebraic counterpart of the deductive machinery could be found. Since the inception of da Costa's paraconsistent calculi, an algebraic equivalent for such systems have been searched. It is known that these systems are non self-extensional (i.e., they do not satisfy the replacement property). More than this, they are not algebraizable in the sense of Blok-Pigozzi. The same negative results hold (...) for several systems of the hierarchy of paraconsistent logics known as Logics of Formal Inconsistency (LFIs). Because of this, these logics are uniquely characterized by semantics of non-deterministic kind. This paper offers a solution for two open problems in the domain of paraconsistency, in particular connected to algebraization of LFIs, by obtaining several LFIs weaker than C1, each of one is algebraizable in the standard Lindenbaum-Tarski's sense by a suitable variety of Boolean algebras extended with operators. This means that such LFIs satisfy the replacement property. The weakest LFI satisfying replacement presented here is called RmbC, which is obtained from the basic LFI called mbC. Some axiomatic extensions of RmbC are also studied, and in addition a neighborhood semantics is defined for such systems. It is shown that RmbC can be defined within the minimal bimodal non-normal logic E+E defined by the fusion of the non-normal modal logic E with itself. Finally, the framework is extended to first-order languages. RQmbC, the quantified extension of RmbC, is shown to be sound and complete w.r.t. BALFI semantics. (shrink)

Suppose that a decision-maker's aim, under certainty, is to maximise some continuous value, such as lifetime income or continuous social welfare. Can such a decision-maker rationally satisfy what has been called "continuity for easy cases" while at the same time satisfying what seems to be a widespread intuition against the full-blown continuity axiom of expected utility theory? In this note I argue that the answer is "no": given transitivity and a weak trade-off principle, continuity for easy cases violates the anti-continuity (...) intuition. I end the note by exploring an even weaker continuity condition that is consistent with the aforementioned intuition. (shrink)