[The author first examines the application of the qualificatio theologica or theological norm as an aid to doctrinal interpretation in Catholic neo-Scholastic theology. He then explores the emergence of related interpretive questions at Vatican II, particularly with regard to two sections of Lumen gentium. His examination suggests a hermeneutical principle for interpreting the documents of Vatican II, namely the importance of being attentive to the nature of the council as a transitional event in Catholic theology. His study also highlights the continuing need for a consistent method of qualifying doctrinal statements.]