Realist, phenomenalist, and pragmatist perspectives on scientific theories. Review of conventional textbook quantum mechanics. Local causality and signal locality. Elements of formal measurement theory and wave function collapse; decoherence and the classical/quantum boundary. Copenhagen interpretation of quantum mechanics. Operationalist quantum mechanics. Hidden variable theories: possibilities and problems. Contextuality and nonlocality; Bell's theorem. Bohm deBroglie theory and generalizations. Modal interpretations and consistent histories quantum mechanics of Gell-Mann, Hartle, Omnes. Relative state interpretations (Everett's "many worlds," more recent work by Wallace and Carroll). Quantum Darwinism. QBism. Relational Quantum Mechanics. A sketch of collapse theories.