The notion of the 'spirit' is dazzling: it has manifold meanings and plays a crucial role in Early Modern medicine, psychology, religion, natural philosophy and cosmology. This book explores how those disciplines conceived of the spirits and shows that knowledge of the spirits is an essential prerequisite for the understanding of Renaissance literature and music. The volume focusses on the way in which the spirits act upon the soul's perception, imagination and cognition, and on the cultural practices which aim to use or to purge or to ban the spirits.