In this book, Allan Kardec approaches divine justice from the point of view of Spiritism. The first part is a comparative analysis of the concepts of different faiths about heaven, purgatory and hell, angels and demons, and future punishments and rewards. The dogma of eternal punishments is specially discussed and refuted by arguments taken from the laws of nature. The second part presents numerous communications with spirits in different situations, and which shed light on the state of the soul after death and its passage from the physical life to the spirit life, which until then had been obscure and feared. It is a sort of travel guide to be used before we enter into a new world!