FERNANDA BIROLLI ABRAHÃO

This project aims to study the concept of truth in formal theories. How should we understand the notion of formal truth in a consistent way? This engenders a number of problems, the Liar's paradox being one of the main ones. There are some alternatives to solve it towards a formal notion of truth. The first one gives as a solution the abandonment of classical logic and adopts non-classical logics. The second is composed of different strategies, united by the fact that they intend to maintain classical logic and, to do so, restrict the principles of capture and release (which will be exposed in the thesis). The third alternative turns to some substructural approaches, which, unlike the others, shape deep structures of logical reasoning to solve the paradox. Keywords: truth; paradox; classical logic; heterodox logics; substructures.