26 research outputs found
Intuitionism and the Modal Logic of Vagueness
Intuitionistic logic provides an elegant solution to the Sorites Paradox. Its acceptance has been hampered by two factors. First, the lack of an accepted semantics for languages containing vague terms has led even philosophers sympathetic to intuitionism to complain that no explanation has been given of why intuitionistic logic is the correct logic for such languages. Second, switching from classical to intuitionistic logic, while it may help with the Sorites, does not appear to offer any advantages when dealing with the so-called paradoxes of higher-order vagueness. We offer a proposal that makes strides on both issues. We argue that the intuitionistâs characteristic rejection of any third alethic value alongside true and false is best elaborated by taking the normal modal system S4M to be the sentential logic of the operator âit is clearly the case thatâ. S4M opens the way to an account of higher-order vagueness which avoids the paradoxes that have been thought to infect the notion. S4M is one of the modal counterparts of the intuitionistic sentential calculus and we use this fact to explain why IPC is the correct sentential logic to use when reasoning with vague statements. We also show that our key results go through in an intuitionistic version of S4M. Finally, we deploy our analysis to reply to Timothy Williamsonâs objections to intuitionistic treatments of vagueness
Fronteiras contingentes e conhecimento limitado
Este artigo mostra que combinando as noçÔes lĂłgicas de 'contingĂȘncia' e 'conhecimento' nĂłs podemos formular uma tese cĂ©tica de acordo com a qual 'o mundo nĂŁo pode ser conhecido'. AlĂ©m disso, ele mostra que tal tese Ă© plausĂvel do ponto de vista epistemolĂłgico
A Non-standard kripke semantics for the minimal deontic logic
In this paper we study a new operator of strong modality â, related to the non-contingency operator â. We then provide soundness and completeness theorems for the minimal logic of the â-operatorCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTĂFICO E TECNOLĂGICO - CNPQCOORDENAĂĂO DE APERFEIĂOAMENTO DE PESSOAL DE NĂVEL SUPERIOR - CAPESFUNDAĂĂO DE AMPARO Ă PESQUISA DO ESTADO DE SĂO PAULO - FAPESP001403272/2019-02016/25891-
Interplays of knowledge and non-contingency
This paper combines a non-contingency logic with an epistemic logic by means of fusions and products of modal systems. Some consequences of these interplays are pointed out
Two Temporal Logics of Contingency
This work concerns the use of operators for past and future con-tingency in Priorean temporal logic. We will develop a system namedCt, whose language includes a propositional constant and prove that(i) Ct is complete with respect to a certain class of general frames and(ii) the usual operators for past and future necessity are denable insuch system. Furthermore, we will introduce the extension Ctlin thatcan be interpreted on linear and transitive general frames. The theo-retical result of the current work is that contingency can be treatedas a primitive notion in reasoning about temporal modalities
The Boxdot Conjecture and the Language of Essence and Accident
We show the Boxdot Conjecture holds for a limited but familiar range of Lemmon-Scott axioms. We re-introduce the language of essence and accident, first introduced by J. Marcos, and show how it aids our strategy