Truth and paradox: consequences of the liar's paradox for formal theories of truth

• Grant number: 21/08273-2
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Start date: December 28, 2021
• End date: June 27, 2022
• Field of knowledge: Humanities - Philosophy - Logic
• Principal Investigator: Edelcio Gonçalves de Souza
• Grantee: Fernanda Birolli Abrahão
• Supervisor: Graham George Priest
• Host Institution: Faculdade de Filosofia, Letras e Ciências Humanas (FFLCH). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: City University of New York (CUNY), United States
• Associated to the scholarship: 20/02402-2 - Truth and paradox: consequences of the liar's paradox for formal theories of truth, BP.MS

Abstract

One of the main problems that arise when constructing formal theories of truth is undoubtedly the Liar's Paradox. A sentence that seems to be true and false at the same time comes as a threat, at least at first glance, to a coherent concept of truth. How can we solve this issue towards a coherent formal theory of truth? There are three possible alternatives: the classical solutions, the heterodox solutions and the substructural solutions. The first field is composed of different strategies, united by the fact that they intend to maintain the classical logic and, for that, restrict Tarski's Capture - Release principles. The second gives as solution the abandonment of certain classical principles, such as the Law of Excluded Middle or the Ex Contradictione Quolibet, and thus moves to a non-classical setting. The third alternative turns to substructural approaches, which, unlike the others, mold deep structures of the logical reasoning to solve the paradox. Hence, the purpose of this internship project is to investigate the panorama of the three possible fields of solutions to the Liar's Paradox, having as advisor abroad Prof. Dr. Graham Priest at the City University of New York (CUNY). Taking advantage of the fruitful discussions happening in Prof. Priest's research group, I aim to focus the study on non-classical solutions to the paradox, thoroughly investigating paraconsistent, paracomplete and dialetheist logics on how each one of them understands the concept of truth and aims to solve the paradox. (AU)