Encyclical

Encyclical, a term used to denote a circular letter addressed by a religious superior to those in his charge. The name is now generally restricted to a letter issued by the Pope to the Bishops of the Roman Church, and embodying the Papal opinion or decision upon some point of faith, morals, or discipline. It is a favourite instrument of the present Pope (Leo XIII.), just as the Allocution was the instrument preferred by the late Pope Pius IX.