Rivail came to the seance table a sceptic of standing: a disciple of Pestalozzi, author of school textbooks, member of learned societies. Invited in 1855 to observe the table-turning phenomena then fashionable in Paris, he judged that behind the parlour effects lay something worth methodical study, and he proceeded like the educator he was, drafting ordered questions on God, the universe, the spirits and human destiny, and putting them through mediums, chiefly young women writing in trance, while comparing answers across different mediums and circles for consistency.
The Spirits' Book presents the harvest. Its four parts move from first causes, God, creation, the vital principle, through the spirit world, the nature and origin of spirits, reincarnation, the return to the body, and the occupations of the spirit life, to moral laws, worship, labour, justice, love of neighbour, and finally to hopes and consolations, the future life and the nature of suffering. The doctrine that emerges is optimistic and progressive: no eternal damnation, but education of the spirit across as many lives as improvement requires; inequalities of birth explained as differences of a soul's age and past choices; charity, in the formula the movement made its motto, as the condition of salvation. Kardec signed the work with a Gallic pen name, taken, he said, from a prior incarnation, to separate the codifier's task from the schoolmaster's reputation.