A special issue examining the Principle of Identity of Indiscernibles, its counterexamples, modal status, and implications across metaphysics and philosophy of science.
Guest Editor: Leonardo G. S. Videira (University of São Paulo – FAPESP)
The Principle of Identity of Indiscernibles (PII), in its most widespread formulation, states that any two things sharing all the same properties are in fact identical; in other words, no two distinct things share all their properties.
Despite its apparent simplicity, the principle has remained one of the most contested theses in the history of metaphysics. Classical and contemporary counterexamples—including Kant's droplets, Black's spheres, and entangled bosons—appear to involve numerically distinct yet indiscernible entities, thereby challenging the principle's truth.
Debates concerning the PII extend well beyond the question of its truth or falsity, however. They encompass issues concerning the interpretation of its constituent notions, the modal status of the principle, and the nature of the necessity, if any, that underwrites it.
Moreover, the PII plays a central role in a wide range of philosophical discussions, including the dispute between bundle and substratum theories, the ontology of quantum mechanics, the metaphysics of mathematical objects, and the relationship between indiscernibility and identity.
The last two decades have witnessed significant developments in these debates. This special issue aims to bring together contributions that advance our understanding of the PII, its implications, and its applications across different areas of philosophy.
Submissions may address, but are not limited to, the following topics:
Submission deadline: September 20, 2026
Accepted papers will be published in late 2026 or early 2027.
Author guidelines: Manuscrito author guidelines
Submission portal: Manuscrito Editorial Manager
Please indicate in your submission that the manuscript is intended for the special issue on the Principle of Identity of Indiscernibles.
For further information, please contact:
Leonardo G. S. Videira leonardo.soutello@gmail.com