"The Spirits' Book" is the foundational work of Spiritism, a school of thought first established in France in the mid-nineteenth century by the French educator Allan Kardec. Currently, Spiritism includes over fifteen million adherents, the eleventh largest spiritual following worldwide, ahead of more historically traditional religions such as Judaism (twelfth) and Jainism (fourteenth).This new translation is based on painstaking research of the French text, so as to provide the most faithful rendering in English of Kardec's seminal work. Several original editions in French were analyzed, comparing all the changes that Kardec himself made to the text, with copious notes that allow any reader to reconcile the translation with the source text in French. This translation also carefully analyzes the nuances in meaning and usage of vocabulary (in both French and English), as well as different stylistic choices that must be made in English, striking a balance between literal accuracy and readability. "The Spirits' Book" represents a philosophical guide for real people, encompassing the analysis of all the fundamental questions underpinning human existence.