Popper's Propensity Interpretation of Probability and Quantum Mechanics

This paper is a critique of Popper's interpretation of quantum mechanics and the claim that the propensity interpretation of probability resolves the foundational problems of the theory. The first two sections are purely expository. In section 1, I sketch Popper's conception of a formal theory of probability and outline the propensity interpretation. Section 2 is a brief description of the gist of Popper's critique of the Copenhagen interpretation of quantum mechanics and his proposed solution to the measurement problem (the problem of the "reduction of the wave packet"). In section 3, I show that the propensity interpretation of probability cannot resolve the foundational problems of quantum mechanics, and I argue for a thesis concerning the significance of the transition from classical to quantum mechanics, which I propose as a complete solution to these problems. Finally, section 4 contains some general critical remarks on Popper's approach to the axiomatization and interpretation of formal theories of probability.