Abstract

This dissertation is about the ontologies of the main interpretations and theories of non-relativistic quantum mechanics, and about issues regarding how observers are represented in quantum mechanics. I have two main theses, which I don't argue for explicitly, but which are implicitly defended in the context of my discussion of the various interpretations and theories. ;My first thesis is that the ontologies of the various interpretations and theories are importantly incomplete---there are important ways in which they do not tell a full story about what exists in the world. My second thesis is that to judge to what extent an interpretation or theory of quantum mechanics is empirically adequate, one needs to examine how observers are represented in that interpretation or theory. My first and second theses are linked because, by giving an ontology for quantum mechanics, one is specifying what observers are according to quantum mechanics, and what a theory entails about the nature of observers is relevant to determinations of empirical adequacy. ;In the course of defending these two theses, I point out some problems and solve other problems for various versions of quantum mechanics. I discuss the Bare theory, Michael Lockwood's many-minds interpretation, the GRW theory, the Continuous Spontaneous Localization theory, Bohm's interpretation, consciousness collapse theories, David Albert and Barry Loewer's single-mind and many-minds interpretations, and the Copenhagen variant of the modal interpretation. I also discuss the issues of whether belief observables exist, and whether quantum-mechanical self-measurement is possible