Pablo Cobreros

University of Navarra

Inferences and Metainferences

30 November 2018, 16:00

Faculdade de Letras de Lisboa

Sala Mattos Romão (Departamento de Filosofia)

Abstract: The logic ST has been proposed in different places to deal with paradoxes. There is something very interesting about ST: that it is classical logic for a classical language, but that it provides different ways of strengthening classical logic to deal with paradoxes. For example, the logic STT (ST for a language with a transparent truth predicate and self-referential sentences) is a conservative extension of classical logic. That is, STT is not only non-trivial, but it has exactly the same valid inferences as classical logic for the T-free fragment. How is this possible? Well, because ST preserves all classically valid inferences but not some classical metainferences. The question then arises of exactly which are the metainferences of ST. In their (2015) paper Eduardo Barrio, Lucas Rosenblatt and Diego Tajer show that ST metainferences are closely related to LP inferences. In this note we review their result and try to highlight the connection in a broader context.