The first reason, why Pope Pius writes the encyclical, is his desire in the restoration of all things in Christ, which he had defined as his motto in his first Encyclical letter. To Pope Pius, there is no safer or more direct road than Mary. She is uniting all mankind in Christ. The encyclical relied heavily on the views expressed in Saint Louis de Montfort's book True Devotion to Mary. In fact the language of both writings is strikingly similar, which is not surprising, since Saint Pius highly esteemed True Devotion and granted an Apostolic Blessing to all who read it.