On the Overlap Between Everything and Nothing

Graham Priest has recently proposed a solution to the problem of the One and the Many which involves inconsistent objects and a non-transitive identity relation. We show that his solution entails either that the object everything is identical with the object nothing or that they are mutual parts; depending on whether Priest goes for an extensional or a non-extensional mereology.

Rational belief and Dialetheism

It is usually maintained that a subject with manifestly contradictory beliefs is irrational. How can we account, then, for the intuitive rationality of dialetheists, who believe that some manifest contradictions are true? My paper aims to answer this question. Its ultimate goal is to determine a characterization of (or rather a constraint for) rational belief approvable by both the theorists of Dialetheism and its opponents. In order to achieve this goal, a two-step strategy will be adopted. First, a characterization of rational belief applicable to non-dialetheist believers will be determined; this characterization will involve the semantic apparatus of Nathan Salmon’s Millian Russellianism but will get rid of the problematic and obscure notion of mode of presentation (guise in his own terminology), replacing it with a couple of novel devices, belief subsystems and cognitive coordination. Second, using ideas from Graham Priest, the leading proponent of Dialetheism, such a characterization will be modified, so as to devise a new one able to account for the intuitive rationality of both dialetheist and non-dialetheist believers.

Intersubjective approach to intentionality and internal objects

Intentionality — the orientation of mental states to objects (things, properties, states of things, events) — has been considered a hallmark of the psyche since Brentano’s time. In this article, we consider the problem of intentionality from the second-person approach, or the standpoint of intersubjectivity. Our analysis shows that intentionality is intrinsically projective. The projective nature of intentionality is related to internal objects that play a crucial role in fixing the person’s subjective experience and serve as a fulcrum in the development of the person. The internal object can be treated as a set of properties and tropes. The logic of intentionality proposed by Graham Priest and the theory of primary (that is, belonging to the Freudian system «unconscious») psychological attitudes developed by Linda Brakel created the preconditions for seman- tical analysis of projective intentionality. In the article, we rely on the logic of projective intentionality that reorients the resources of modal logics and semantics of possible worlds to the investigation and formalization of primary thinking. Considering the problem of mental existence within the framework of the second-person approach, we show that Wittgenstein’s reasoning about the «beetle in a box» does not refute the thesis of the privacy of mental meanings. Finally, involving the possible world semantics, we develop a neo-Aristotelian approach to the ontology of mental objects.

Esticando a verdade sem alcançar a contradição: o caso do dialeteísmo

Dialeteias são contradições verdadeiras. Dialeteísmo é a visão de que há dialeteias e dialeteístas são aqueles que defendem tal visão. Uma das principais motivações para o dialeteísmo encontra-se nos paradoxos semânticos, como o paradoxo do Mentiroso. A sentença do mentiroso, na abordagem dialeteísta, instancia uma dialeteia. O problema é: como aceitar contradições verdadeiras? Como dialeteísmo é a visão que algumas, mas não todas, contradições são verdadeiras, o dialeteísmo demanda um tratamento paraconsistente. Porém, não é qualquer sistema paraconsistente que pode ser aplicado ao dialeteísmo. A interpretação do símbolo de negação deve ser um operador formador de contradição (ofc) com o sentido relevante para a aplicação dialeteísta. Especificamente, na versão de dialeteísmo que discutiremos nesse artigo, defendida por Graham Priest, temos que, para que o dialeteísmo faça sentido, a negação da lógica subjacente deve atender a dois requisitos: (i) ser um ofc e (ii) não ser explosiva. A Lógica do Paradoxo (LP) tem sido apontada como a lógica adequada ao dialeteísmo. Veremos que, a fim de lidar com contradições sem trivialidade, dialeteístas “esticam” a verdade de modo que a verdade possa incluir, em alguns casos, a falsidade também. Nesse caso, haveria sentenças verdadeiras e falsas, chamadas de aglutinações de valores de verdade (truth-value gluts). Em LP, aglutinações de valores de verdade são fundamentais para garantir os requisitos (i) e (ii). Todavia, vamos argumentar que tal procedimento de esticar a verdade, permitindo aglutinações, garante a paraconsistência ao custo de distorcer a interpretação da noção de contradição envolvida no dialeteísmo. Especificamente, tal distorção enfraquece a interpretação da negação comprometendo o sentido de contradição relevante para o dialeteísmo. Vamos argumentar que as próprias restrições dialeteístas a uma compreensão adequada do Mentiroso mostram que as condições (i) e (ii) são incompatíveis e que, com isso, o projeto dialeteísta enfrenta consideráveis obstáculos.

Sets, lies, and analogy: a new methodological take

The starting point of this paper is a claim defended most famously by Graham Priest: that given certain observed similarities between the set-theoretic and the semantic paradoxes, we should be looking for a ‘uniform solution’ to the members of both families. Despite its indisputable surface attractiveness, I argue that this claim hinges on a problematic reasoning move. This is seen most clearly, I suggest, when the claim and its underlying assumptions are examined by the lights of a novel, quite general and, I contend, promising take on inter-theoretic analogy. The ensuing discussion is intended to serve as both a possible case study and a first step towards the broader aim of the paper: namely, to initiate a wider conversation on the methodology of paradox-solving on the one hand, and the use of inter-theoretic analogies on the other.

Understanding as a Source of Justification

The traditional epistemological approach towards judgments like BACHELORS ARE UNMARRIED or ALL KNOWLEDGE IS TRUE is that they are justified or known on the basis of understanding alone. In this paper, I develop an understanding-based account which takes understanding to be a sufficient source of epistemic justification for the relevant judgments. Understanding-based accounts face the problem of the rational revisability of almost all human judgments. Williamson has recently developed a reinforced version of this problem: the challenge from expert revisability. This is the problem that even the best candidate judgments for understanding-based justification can be rationally rejected by the relevant experts, who may not even have any disposition or inclination to accept these judgments. (Consider, for instance, Graham Priest, a leading logician who rejects the law of non-contradiction.) However, I argue that expert revisability is fully compatible with the proposed understanding-based epistemology, because expert revisability is true of sufficient sources of epistemic justification in general. A remaining metaphysical worry is that understanding might end up being ‘too thin’ to play the envisaged epistemological role. This worry can be countered with a novel metaphysics of understanding involving second-order dispositions.

Contradiction Club: Dialetheism and the Social World

Putative examples of true contradictions in the social world have been given by dialetheists such as Graham Priest, Richard Routley, and Val Plumwood. However, we feel that it has not been decisively argued that these examples are in fact true contradictions rather than merely apparent. In this paper we adopt a new strategy to show that there are some true contradictions in the social world, and hence that dialetheism is correct. The strategy involves showing that a group of sincere dialetheists can, given an appropriately formed institution, bootstrap contradictions into existence. We discuss objections and consider the implications of this finding for debates over logic.

Análise de Philosophy and Martial Arts de Graham Priest e Damon Young

Nesta resenha apresentamos e avaliamos a coletânea Philosophy and Martial Arts. Será apontado o valor da obra para os estudiosos das artes marciais, da mesma maneira que pondera-se limites das análises. Ao aproximar artes marciais das problemáticas e autores da filosofia, a coletânea evidencia a necessidade desse procedimento analítico. A relevância desse empenho não se dá apenas nos méritos da obra, mas também em algumas lacunas que, sendo assinaladas, podem impactar positivamente análises semelhantes que começam a ser executadas no campo acadêmico da educação física brasileira.

What Counts as Evidence for a Logical Theory?

Anti-exceptionalism about logic is the Quinean view that logical theories have no special epistemological status, in particular, they are not self-evident or justified a priori. Instead, logical theories are continuous with scientific theories, and knowledge about logic is as hard-earned as knowledge of physics, economics, and chemistry. Once we reject apriorism about logic, however, we need an alternative account of how logical theories are justified and revised. A number of authors have recently argued that logical theories are justified by abductive argument (e.g. Gillian Russell, Graham Priest, Timothy Williamson). This paper explores one crucial question about the abductive strategy: what counts as evidence for a logical theory? I develop three accounts of evidential confirmation that an anti-exceptionalist can accept: (1) intuitions about validity, (2) the Quine-Williamson account, and (3) indispensability arguments. I argue, against the received view, that none of the evidential sources support classical logic.