The Multiverse is an introduction to the idea that our universe is just one of many universes. Philosophers have proposed that all logically possible universes are equally real. In physics, the many-worlds interpretation of quantum mechanics proposes that every possible outcome of a quantum event exists in its own world. Leading philosopher Jeremy Butterfield presents and assesses three versions of the idea of the multiverse, one from philosophy and two from physics. He explores the ideas of logically possible worlds, the branches of the quantum state, and the bubbles of inflationary cosmology. For each idea, he selects one philosophical question to explore in depth: what is a possible world, what is chance, and what is explanation? Written for students and newcomers, The Multiverse provides an explanation of leading theories, without requiring any prerequisites in philosophy or physics. This book will lead readers to a proper academic understanding of multiverse proposals in logic, quantum theory, and cosmology.