Communication between the spirit world and the corporeal world is in the nature of things, and has in it nothing supernatural. Traces of its existence are to be found among all nations and in every age; they are now becoming general and evident to all. Spirits assure us that the time appointed by Providence for a universal manifestation of their existence has now come; and that their mission, as the ministers of God and the instruments of His will, is to inaugurate, through the instructions they are charged to convey to us, a new era of regeneration for the human race.

This book is a compilation of their teachings. It has been written by the order and under the dictation of spirits of high degree, for the purpose of establishing the bases of a rational philosophy, free from the influence of prejudices and of preconceived opinions.