The main objective of this book is to show the relationships between natural laws and the concept of true happiness that will be proposed based on the fundamental work of Spiritism: The Spirits' Book.

Continuing his series of explanatory books about The Spirits' Book, which now reaches its third part and its fourth volume. But before commenting on Kardec's work, an activity that he carries out constantly and in depth, the author shows us and demonstrates, with technique, clarity and in an unprecedented way, some important philosophical principles that all revolve around human action.

These are discussions about the concepts of virtues and moral actions, where one cannot pass by inertly when dealing with the great spiritual questions. The good man that exists in potential in each one of us cannot go unpunished from this text. The author provides us with a terrible but necessary push towards the world of achievements.

Furthermore, the commentaries on The Spirits' Book are woven along the fruitful path of oppositions: the positions of Spiritism and materialism are compared in relation to each moral law.