The Multiverse: a Philosophical Introduction

Abstract

This book is a philosopher's introduction to the idea that our universe is just one of many universes. I present and assess three versions of the idea: one version from philosophy, and two from physics. In short, they are: all the logically possible worlds; all the branches of the quantum state, in an Everettian interpretation of quantum theory; and all the bubbles of inflationary cosmology. For each proposal, I choose one main philosophical question to discuss in depth. They are, respectively: what is a possible world; what is chance; and what is explanation. But before treating these proposals and their associated questions, I set the stage by reviewing physics and philosophy from about 1600 to about 1900; and a final Chapter compares and contrasts the proposals.