54 While treating of education, it is not out of place to show here how an ecclesiastical writer, who flourished in more recent times, during the Renaissance, the holy and learned Cardinal Silvio Antoniano, to whom the cause of Christian education is greatly indebted, has set forth most clearly this well established point of Catholic doctrine. He had been a disciple of that wonderful educator of youth, St. Philip Neri; he was teacher and Latin secretary to St. Charles Borromeo, and it was at the latter's suggestion and under his inspiration that he wrote his splendid treatise on The Christian Education of Youth . In it he argues as follows: The more closely the temporal power of a nation aligns itself with the spiritual, and the more it fosters and promotes the latter, by so much the more it contributes to the conservation of the commonwealth. For it is the aim of the ecclesiastical authority by the use of spiritual means, to form good Christians in accordance with its own particular end and object; and in doing this it helps at the same time to form good citizens, and prepares them to meet their obligations as members of a civil society. This follows of necessity because in the City of God, the Holy Roman Catholic Church, a good citizen and an upright man are absolutely one and the same thing. How grave therefore is the error of those who separate things so closely united, and who think that they can produce good citizens by ways and methods other than those which make for the formation of good Christians. For, let human prudence say what it likes and reason as it pleases, it is impossible to produce true temporal peace and tranquillity by things repugnant or opposed to the peace and happiness of eternity.
Source: Divini Illius Magistri (Vatican.va)