The book "The Purpose of the Papacy" is a study of the history and role of the papacy in the Christian church. Author John S. Vaughan explores the nature of the papacy, its functions, and its meaning for the faithful. The book reveals the historical context of the emergence of the papacy, and also traces its development over the centuries. The author also draws attention to complex issues related to the power of the pope, his mission and interaction with other church institutions. "The Purpose of the Papacy" is a detailed analysis of a topic of interest to both religious professionals and a wide range of readers interested in the history and philosophy of religion.