This book analyzes metaphysical consequences of the quantum theory of many particles with respect to the fundamental notions of identity, individuality and discernibility. The main focus is on the proper interpretation of the quantum formalism in relation to the role of permutation invariance and the adequate representation of the properties of individual subsystems. Two main approaches to the issue of the individuation of quantum particles are distinguished and thoroughly discussed. These approaches differ radically with respect to their metaphysical consequences – while one of them implies the complete indiscernibility of quantum particles of the same kind, the other one restores the possibility of discerning individual particles by their properties. We connect the problem of quantum individuation and discernibility with an analysis of the concept of quantum entanglement, and we also discuss identity over time and in counterfactual scenarios.

In my dissertation, I discuss one organizing principle and its application in space and time: the principle of the identity of indiscernible (PII), determinism (PII's application in time), and locality (PII's application in space). Organizing principles are those that must be assumed to be a working hypothesis to perform experiments and interpret their results, and so cannot be affected by results of such experiments: PII ("[t]hings which are different must differ in something or must have within themselves some diversity that can be noted" (L529)) that helps us to identify a physical event as "the same" as another physical event. PII can be applied in time as "determinism" that tells us that a physical event can pertain to one and only one trajectory of events, hence it allows us to individuate physical events in time; and it can be applied in space as "locality" allows us to separate one physical system from another, hence it allows us to individuate physical systems in space. My argument and examples in physics only stay in the domain of non-relativistic quantum mechanics. The generalization of the investigation is limited to this realm. There are other domains in physics where I believe organizing principles would work. However, they will be left for future research. My thesis is twofold: First, I will argue that organizing principles are necessary pre-conditions for experimental and theoretical physics, as they allow us to conduct experiments that underwrite physical laws. The corollary here is that since metaphysics constrains (places boundaries on) the various (and contradictory) theories scientists advance and the sorts of experiments they conduct, it is unwarranted to vindicate or refute these principles with an experiment. Second, I will argue that since these three principles are all principles of what it means to be "the same" (in general, in space, in time), then if one of them fails, all of them fail. The corollary here is that, viewed from this lens, some theories that have been advanced in the foundations of quantum mechanics that now appear inconsistent.

This book provides an interdisciplinary approach to one of the most fascinating and important open questions in science: What is quantum mechanics really talking about? In the last decades quantum mechanics has given rise to a new quantum technological era, a revolution taking place today especially within the field of quantum information processing; which goes from quantum teleportation and cryptography to quantum computation. Quantum theory is probably our best confirmed physical theory. However, in spite of its great empirical effectiveness it stands today still without a universally accepted physical representation that allows us to understand its relation to the world and reality.The novelty of the book comes from the multiple perspectives put forward by top researchers in quantum mechanics, from Europe as well as North and South America, discussing the meaning and structure of the theory of quanta. The book comprises in a balanced manner physical, philosophical, logical and mathematical approaches to quantum mechanics and quantum information. Going from quantum superpositions and entanglement to dynamics and the problem of identity; from quantum logic, computation and quasi-set theory to the category approach and teleportation; from realism and empiricism to operationalism and instrumentalism; the book considers from different angles some of the most intriguing questions in the field.From Buenos Aires to Brussels and Cagliari, from Florence to Florianópolis, the interaction between different groups is reflected in the many different articles. This book is interesting not only to the specialists but also to the general public attempting to get a grasp on some of the most fundamental questions of present quantum physics.

Examines the place and role of the identity of indisernibles, which rules out numerically distinct but perfectly similar things, in Leibniz's philosophy.

This edited volume explores the philosophical implications of quantum mechanics. It features papers from venues of the International Ontology Congress (IOC) up to 2016. IOC is a worldwide platform for dialogue and reflection on the interactions between science and philosophy. The collection features philosophers as well as physicists, including David Albert, Harvey Brown, Jeffrey Bub, Otávio Bueno, James Cushing, Steven French, Victor Gomez-Pin, Carl Hoefer, Simon Kochen, Peter Lewis, Tim Maudlin, Peter Mittlestatedt, Roland Omnès, Juha Saatsi, Albert Solé, David Wallace, and Anton Zeilinger. Since the early days of quantum mechanics, philosophers have studied the subject with growing technical skill and fruitfulness. Their efforts have unveiled intellectual bridges between physics and philosophy. These connections have helped fuel the contemporary debate about the scope and limits of realism and understanding in the interpretation of physical theories and scientific theories in general. The philosophical analysis of quantum mechanics is now one of the most sophisticated and productive areas in contemporary philosophy, as the papers in this collection illustrate.

The author argues that quantum theory admits a plurality of interpretations, each aiding further understanding of the theory, but also advocating specifically the Copenhagen Variant of the Modal Interpretation. That variant is applied to topics like the Einstein-Podolsky-Rosen paradox and the problem of 'identical' particles.