Abstract: Quantum theory was developed in response to a welter of new experimental phenomena, yet appeared to depict a world so esoteric as to be literally unimaginable. Interpretation of the theory became feasible only after von Neumann's theoretical unification, but von Neumann's own interpretation astonishingly implied that in measurement something happens that violates Schroedinger's equation, the theory's cornerstone. This book argues first of all that the phenomena themselves, without theoretical motives, suffice to eliminate ’common cause’ models, thus requiring a radical departure from classical physics models. The measurement process, however, has an adequate description of itself as a quantum-mechanical process, so that the theory can be seen as complete in a relevant sense. But the question of interpretation, ‘How could the world possibly be the way this theory says it is?’, is not thereby answered. In response to that question it is argued that the theory admits a plurality of interpretations, each of which helps to understand the theory further, but also advocates one particular interpretation (the Copenhagen Variant of the Modal Interpretation). That interpretation is then applied to such topics as the Einstein–Podolsky–Rosen paradox and the problem of ’identical’ particles, quantum statistics, identity, and individuation.

Keywords: Einstein–Podolsky–Rosen paradox, identical particles, interpretation, modal interpretation, John von Neumann, philosophy of physics, Philosophy of science, quantum measurement problem, quantum statistics, quantum theory, Erwin Schroedinger, Schroedinger's equation