On Easter Sunday 21 April 1878, Pope Leo XIII issued the encyclical Inscrutabili Dei Consilio or On the Evils of Society. This was the first encyclical of his pontificate and stressed many of the themes which would guide his future papacy.
In this encyclical, Pope Leo identifies several threats facing humanity at his time, chiefly that the rejection of objective truth and authority which has led to civil strife and war; the rejection of law; and a desire for the things of this world rather than the eternal. The chief defense against these threats is the Catholic Church, which is why Pope Leo believes it is under attack.
Leo stresses the contributions of the Catholic Church to civilization through science and culture. He also calls for the restoration of Vatican political independence to ensure that the Church can freely exercise its responsibilities in the world.
Even though Pope Leo warns against the evils he perceives in society, he stresses that he wishes to work with the countries and peoples of the world for the advancement of the common good. Furthermore, he encourages the priests and bishops to continue striving to present the truth of the faith in union with the Pope and as expressed by “the great Augustine and the Angelic Doctor, with all other teachers of Christian wisdom…”
One area of particular importance for Leo XIII is the preservation of the sanctity of marriage. It is in the family that the foundation of a moral life begins. The decline of the family means the decline of civilization.
This encyclical really sets the foundation for Leo XIII’s papacy and his view that the problems of the modern world should be solved by the Catholic Church and the governments of the world working together rather than in opposition.