Project title: Formal truth theories
Project duration: 03.2015-03.2018
Principal Investigator: Cezary Cieśliński
Funding organization: National Science Centre (NCN), Poland
Host institution: University of Warsaw, Institute of Philosophy
Project team: Cezary Cieśliński, Michał Tomasz Godziszewski, Joanna Golińska-Pilarek, Taneli Huuskonen, Mateusz Łełyk, Bartosz Wcisło
Project outline

Contemporary conceptions of truth can be divided into two broad categories: philosophical and logical ones. Admittedly the division is not sharp, nor it should be: philosophers need formal results and the logicians often take philosophical intuitions into account in their formal constructions. The present project belongs to the realm of philosophically motivated formal investigations, devoted to the notion of truth.

The main overall goal of the project is to deepen our understanding of the notion of truth, underlying much of both our scientific and everyday thinking. In the project we will study formal theories of truth, with a clear mathematical structure, expressed in formal languages (unlike loose, intuitive conceptions, formulated in natural language). The basic assumption underlying the project is that any intuitive conception of truth has to pass the test of formalization in order to count as valid or at least promising. On the other hand, formalizations, once proposed, can be investigated with rigorous methods and confronted with intuitive conceptions which stand behind them. The results of such a confrontation may then count strongly in favour or against a given formalism. We plan to consider several directions which can lead to the realization of our overall goal and which are connected with open and important questions in this area of research.
The project concentrates primarily on axiomatic theories of truth and it involves carrying out a comprehensive and systematic research on these theories. It comprises four main tasks, which are listed below. Even partial realization of these tasks can have important consequences not only for philosophy and logic, but also for theoretical and methodological foundations of formal and cognitive sciences.

Task 1: Analysis of formal properties of classical truth theories
Task 2: Truth theories in non-classical logics
Task 3: Analysis of semantic paradoxes in truth theories
Task 4: Philosophical interpretations of truth theories