After introducing the empiricist point of view in philosophy of science, and the concepts and methods of the semantic approach to scientific theories, Professor van Frassen discusses quantum theory in three stages. First, he examines the question of whether and how empirical phenomena require a non-classical theory, and what sort of theory they require, then, the mathematical foundations of quantum theory with special reference to developments in the modelling of interaction, composite systems, and measurement, and, finally, the author broaches the main questions of interpretation. Includes an Index.

(Key Words: Quantum Mechanics, Empiricists, Physics, Philosoph of Science, Determinism, Max Plank, Bas C. van Fraassen, Werner Heisenberg, Erwin Schroedinger).