Columbia subject headings:
Harvard subject headings:
Lotze, Hermann, 1817-1881.
Mill, John Stuart, 1806-1873
Spencer, Herbert, 1820-1903.
Princeton subject headings:
Lotze, Hermann, 1817-1881.
Mill, John Stuart, 1806-1873.
Philosophy--History--19th century.
Spencer, Herbert, 1820-1903.