This book presents a comprehensive account of a new member of the family of the modal interpretations of quantum mechanics. According to the modal-Hamiltonian interpretation, the Hamiltonian of the quantum system plays a decisive role in the definition of systems and subsystems, and in the rule that selects the observables whose possible values become actual. This book begins by introducing the main interpretative postulates and by proving their Galilean invariance. Also discussed herein is an argument for the physical relevance of the interpretation.

According to the modal interpretation, the standard mathematical framework of quantum mechanics specifies the physical magnitudes of a system, which have definite values. Probabilities are assigned to the possible values that these magnitudes may adopt. The interpretation is thus concerned with physical properties rather than with measurement results: it is a realistic interpretation (in the sense of scientific realism). One of the notable achievements of this interpretation is that it dissolves the notorious measurement problem. The papers collected here, together with the introduction and concluding critical appraisal, explain the various forms of the modal interpretation, survey its achievements, and discuss those problems that have yet to be solved. Audience: Philosophers of science, theoretical physicists, and graduate students in these disciplines.

Modal interpretations provide a general framework within which quantum mechanics can be considered as a theory that describes reality in terms of physical systems possessing definite properties. Modal interpretations are relatively new attempts to present quantum mechanics as a theory which, like other physical theories, describes an observer-independent reality. In this book, Pieter Vermaas details the results of this work. He provides both an accessible survey and a systematic reference work about how to understand quantum mechanics using a modal interpretation. The book will be of great value to undergraduates, graduate students and researchers in philosophy of science and physics departments with an interest in learning about modal interpretations of quantum mechanics.