A companion to his first book, The Spirits' Guide, The Book on Mediums explains how to apply Allan Kardec's principles of his practical science of spiritism in

THE PRINCIPLES OF SPIRITISMABOUT THE IMMORTALITY OF THE SOUL, THE NATURE OF SPIRITS AND THEIR INTERACTIONS WITH HUMANKIND, MORAL LAW, PRESENT LIFE, FUTURE LIFE

Wanting to popularize Spiritism and make spreading it easier and quicker, but without prejudicing the basic works of the Spiritist Doctrine, Allan Kardec wrote

“Un deseo muy natural, entre las personas que se ocupan del Espiritismo, es el poder entrar por sí mismas en comunicación con los Espíritus; esta obra est�