A carregar...
Publicação
On the Topic of Impossibility: a question-sensitive impossible worlds approach to logical omniscience
| Nome: | Descrição: | Tamanho: | Formato: | |
|---|---|---|---|---|
| 1.38 MB | Adobe PDF |
Autores
Orientador(es)
Resumo(s)
Desde que Hintikka (1962) propôs uma lógica epistémica modal com base na semântica de mundos possíveis que rapidamente se colocou o problema da omnisciência lógica, isto é, de que a lógica em questão implica que os agentes sabem tudo o que se segue logicamente do que sabem. O próprio Hintikka (1975) tentou resolver o problema introduzindo “mundos possíveis impossíveis”. Desde então, os mundos impossíveis têm sido aplicados no tratamento de várias outras questões filosóficas. Berto e Jago (2019) desenvolvem e exploram várias delas.
A presente dissertação começa com uma avaliação em detalhe de soluções para o problema da omnisciência lógica que aceitam mundos impossíveis. De forma a melhor considerar esta perspetiva, questões sobre a caracterização da natureza dos mundos impossíveis e de como representam são consideradas.
Por outro lado, filósofos como Yalcin (2018) propõem dar resposta ao problema da omnisciência lógica sem acrescentar mundos impossíveis, mas sim tendo por base uma extensão da noção do conteúdo de frases e estados mentais. De acordo com esta segunda família de perspetivas, o conteúdo de uma frase não é dado simplesmente em termos de condições de verdade, mas também em termos daquilo sobre aquilo que a frase versa. O conhecimento de agentes seria fechado sob implicação lógica que não adiciona nenhum novo assunto ao das proposições que o agente sabe, mas não sob implicação lógica simpliciter.
Esta segunda família de perspetivas será igualmente considerada, começando pela questão de o que são assuntos, e terminando por considerar se as várias perspetivas disponíveis conseguem dar conta de todas as diferenças entre conteúdos face aos quais agentes podem ter atitudes proposicionais distintas.
Finalmente, será desenvolvida uma solução para o problema da omnisciência lógica que aceita tanto mundos impossíveis, como uma relativização a questões ou assuntos.
Ever since Hintikka (1962) proposed an epistemic logic based on possible worlds semantics, the problem of logical omniscience, that is, that the logic proposed by Hintikka would have as a consequence that agents know all the logical consequences of what they know, has been posed as a challenge. Hintikka (1975) himself tried to meet the challenge by introducing “impossible possible worlds”. Since then, impossible worlds have been applied to the treatment of various philosophical questions. Berto and Jago (2019) develop and explore several of them. The present dissertation starts by considering in detail solutions for it that accept impossible worlds. In order to more fully consider this family of perspectives, questions regarding the nature of impossible worlds and how they represent are discussed. On the other hand, philosophers like Yalcin (2018) propose to give a solution to the problem of logical omniscience without adding impossible worlds to a standard possible worlds framework, but rather accepting an extension of the notion of the content of statements and mental states. According to this second family of perspectives, the content of a statement is not simply given in terms of truth-conditions, but also in terms of what the statement is about. Agents’ knowledge would be closed entailment that does not add any new subject matter to the subject matter of what the agent knows, not under logical consequence simpliciter. This second family of perspectives will also be considered, starting from the question of what subject matters and including others, such as whether various perspectives on offer are able to account for all the distinctions between contents to which agents might have different propositional attitudes. Finally, a solution for the problem of logical omniscience that accepts both impossible worlds and subject matters will be developed.
Ever since Hintikka (1962) proposed an epistemic logic based on possible worlds semantics, the problem of logical omniscience, that is, that the logic proposed by Hintikka would have as a consequence that agents know all the logical consequences of what they know, has been posed as a challenge. Hintikka (1975) himself tried to meet the challenge by introducing “impossible possible worlds”. Since then, impossible worlds have been applied to the treatment of various philosophical questions. Berto and Jago (2019) develop and explore several of them. The present dissertation starts by considering in detail solutions for it that accept impossible worlds. In order to more fully consider this family of perspectives, questions regarding the nature of impossible worlds and how they represent are discussed. On the other hand, philosophers like Yalcin (2018) propose to give a solution to the problem of logical omniscience without adding impossible worlds to a standard possible worlds framework, but rather accepting an extension of the notion of the content of statements and mental states. According to this second family of perspectives, the content of a statement is not simply given in terms of truth-conditions, but also in terms of what the statement is about. Agents’ knowledge would be closed entailment that does not add any new subject matter to the subject matter of what the agent knows, not under logical consequence simpliciter. This second family of perspectives will also be considered, starting from the question of what subject matters and including others, such as whether various perspectives on offer are able to account for all the distinctions between contents to which agents might have different propositional attitudes. Finally, a solution for the problem of logical omniscience that accepts both impossible worlds and subject matters will be developed.
Descrição
Palavras-chave
Possibilidade Omnisciência Lógica epistémica Teses de mestrado - 2022