A wide and deep study on the Principle of Identity of Indiscernibles: from its constitution to its application in the sciences

• Grant number: 24/17015-5
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: January 01, 2025
• End date: December 31, 2027
• Field of knowledge: Humanities - Philosophy - Epistemology
• Principal Investigator: Osvaldo Frota Pessoa Junior
• Grantee: Leonardo Gomes de Soutello Videira
• Host Institution: Faculdade de Filosofia, Letras e Ciências Humanas (FFLCH). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The Principle of the Identity of Indiscernibles (PII) has long been a notoriously controversial topic in Metaphysics. However, in recent years, these controversies have spilled over into debates within the Philosophy of Physics, Mathematics, and Logics, directly influencing issues in these fields (e.g., determining the correct ontology of Quantum Mechanics, identifying vertices in unlabeled graphs, or assessing whether the Principle of Identity can be grounded in some other notion). This research aims to analyze the fundamental metaphysical notions underlying the postulation of PII and its counterexamples, in order to evaluate the solutions presented in recent debates on PII-without neglecting historically significant responses-and to either strengthen established positions or propose new solutions when the available ones prove inadequate. The research can be divided into three main lines of inquiry. The first addresses the fundamentally metaphysical controversies regarding the constitution of PII; the second deals with historical and taxonomical issues in the debate over the truth or falsity of PII, one of which is the effectiveness of the defense of PII based on inconceivability, originally proposed in the researcher's doctoral thesis; finally, the third line examines how the debate on PII influences and is influenced by issues in other fields, such as those mentioned above, where the inconceivability defense will also be applied. If successful, this research could contribute both to the resolution of long-standing metaphysical problems and to recent foundational issues in other areas. Nevertheless, in a worst-case scenario, whether the original solutions proposed by this research fail, it will still provide an updated historical study that organizes the pro and con arguments regarding PII, thereby facilitating future studies by other researchers.