Just So Non-Catholics Might Understand What Is Happening.

 
An encyclical is a formal, pastoral letter written by the Pope, or under his authority, to the Roman Catholic Church's bishops, and sometimes to all Christians, on matters of doctrine, morals, or discipline, addressing important contemporary issues. The word comes from the Late Latin encyclicus, meaning "circular" or "general," and historically referred to any circular letter from a bishop. Today, the term almost exclusively applies to papal documents.