Kardec's Le Livre des Esprits (The Spirits' Book), published in 1857, set out Spiritism's core teaching: that spirits of the dead survive and progress across successive reincarnations, communicating through mediums to guide the living toward moral improvement. He followed it with Le Livre des Mediums (The Book on Mediums, 1861), a practical manual for mediumistic practice, and founded the Revue Spirite in 1858, a journal that gave the movement its ongoing platform.
Kardec died in Paris on 31 March 1869, but the doctrine he codified took root far more deeply abroad than in France, above all in Brazil, where Kardecist Spiritism grew into one of the country's most significant religious movements, blending with local devotional practice in forms scholarship on the subject, including work on the closely related Cuban Mesa Blanca tradition, has documented extensively. The atlas's Spiritism content, including prayers and rituals attributed to the tradition he founded, follows from the framework he set out in 1857. Kardecist Spiritism differs from Anglo-American spiritualism in treating reincarnation as central rather than incidental, and in presenting itself as a codified moral and philosophical system with its own institutions, journals and charitable works rather than as a loose set of mediumistic practices, a structural difference scholars trace directly to Kardec's own background as an educator building a coherent curriculum rather than recording isolated phenomena.