The world in the wave function : a metaphysics for quantum physics What are the ontological implications of quantum theories that is what do they tell us about the fundamental objects that make up our world How should quantum theories make us reevaluate our classical conceptions of the basic constitution of material objects and ourselves Is there fundamental quantum nonlocality This book articulates several rival approaches to answering these questions ultimately defending the wave function realist approach. It is a way of interpreting quantum theories so that the central object they describe is the quantum wave function interpreted as a field and that the nonseparability and nonlocality we seem to find in quantum mechanics are ultimately manifestations of a more intuitive separable and local picture in higher dimensions. quantum mechanics quantum field theory wave function wave function realism measurement problem macro object problem primitive ontology quantum entanglement quantum nonlocality quantum ontology