Columbia subject headings:
Civilization, Western--History--20th century.
Conservatism--History--20th century.
Harvard subject headings:
Christianity and politics--History--20th century
Conservatism--Europe--History--20th century.
Europe--Politics and government--20th century.
Religion and politics--Europe--History--20th century.
Princeton subject headings:
Catholic Church--Doctrines.
Catholic Church--History.
Church and state--Catholic Church.