Logical Force in Freges Logic

• Grant number: 23/17708-8
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: August 01, 2024
• End date: May 31, 2028
• Field of knowledge: Humanities - Philosophy - Epistemology
• Principal Investigator: Marco Antonio Caron Ruffino
• Grantee: Quirin Josef Colares Oberrauch
• Host Institution: Instituto de Filosofia e Ciências Humanas (IFCH). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

My project investigates the question whether there is a logical distinction between thinking and judging a thought, i. e. whether a thought is just grasped or also judged as true, and explores its possible generalizations as a dynamic interaction between the semantics and pragmatics of language. Due to this distinction, Gottlob Frege analysed the logical structure of judgment into assertoric force and propositional content. The distinction accounts for the difference of illocutionary force and identity of propositional content in judging and thinking a thought. The presence or absence of assertoric force is what differs in judging from thinking the same propositional content. Frege deemed the corresponding formalization of judgment to be a cornerstone of his revolutionary formalization of predicate logic in Begriffschrift (1879). Therefore, it seems odd that in modern logic, which was initiated by the Begriffsschrift, the distinction seems largely forgotten, ignored or located on the mundane (non-logical) side of the philosophy of language. The development was informed by the early reception of Frege's work. Bertrand Russell was at the same time sympathetic and skeptical about the logical significance of the distinction. Ludwig Wittgenstein pointed out the dilemma: Either its meaning is non-logical or it has no meaning at all. That the latent philosophical problem resurfaces in the recent debate is a symptom for its remaining relevance. My project contributes to its resolution, both systematically and exegetically, by the thesis that the logical meaning of the distinction between thinking and judging a thought is necessary for logical inference. It is therefore essential to logic. Thus, my project engages with Marco Ruffino's recent work on the pragmatics within logic and mathematics under a Fregean perspective.