Introduction: Individuality, Distinguishability, and (Non-)Entanglement.

In particular, the four papers address the following issues: In his paper "How to justify the symmetrization postulate in quantum mechanics", Tomasz Bigaj examines the question of how quantum mechanics justifies the Symmetrisation Postulate - mainly with respect to many particle systems. Still, these distinguishable particles cannot be those that are labelled by the tensor product indices "1" and "2", since both particle 1 and particle 2 - if there is any such particle - would be in the same mixed state. For example, in such a state (1) there apparently is a particle located at I R i with spin-up and another particle located at I L i with spin-down; two (not merely weakly) distinguishable particles apparently emerge within such states. [Extracted from the article]