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.