Columbia subject headings:
Apologetics--Early works to 1800.
Apologetics--History--18th century.
Christianity--Philosophy.
Natural theology--Early works to 1800.
Religion--Philosophy.
Harvard subject headings:
Apologetics--Early works to 1800
Christianity--Philosophy
Natural theology--Early works to 1900.
Princeton subject headings:
Apologetics--Early works to 1800.
Apologetics--History--18th century.
Christianity--Philosophy.
Natural theology--Early works to 1800.