The concept of the world soul is difficult to understand in large part because over the course of history it has been invoked to very different ends and within the frameworks of very different philosophical systems, with very different concepts of the world soul emerging as a result. This volume brings together eleven chapters by leading philosophers in their respective fields that collectively explore the various ways in which this concept has been understood and employed, covering the following philosophical areas: Platonism, Stoicism, Medieval, Indian (Vedāntic), Kabbalah, Renaissance, Early Modern, German Romanticism, German Idealism, American Transcendentalism, and contemporary quantum mechanics and panpsychism theories. In addition, short reflections illuminate the impact the concept of the world soul has had on a small selection of areas outside of philosophy: harmony, biology (spontaneous generation), the music of Henry Purcell, psychoanalysis, and Gaia theories.