The Theory of Canon Law is a comprehensive text for anyone who studies canon law at universities or different legal religious institutions. This book, compiled by scholars teaching the theory of law, canon law and its history at the Catholic Theological Faculty, fills the gap in legal literature written in Czech and aspires to become a textbook of this subject for generations to come. The book contains extensive indexes as well as 88 legal rules from Boniface VIII’s Sixth Book, which has not lost any of its topicality.