Columbia subject headings:
Darwin, Charles, 1809-1882--Ethics.
Ethics, Modern--20th century.
Freud, Sigmund, 1856-1939--Influence.
Marx, Karl, 1818-1883--Ethics.
Harvard subject headings:
Darwin, Charles, 1809-1882--Ethics.
Ethics, Modern--20th century.
Freud, Sigmund, 1856-1939--Influence.
Marx, Karl, 1818-1883--Ethics.
Princeton subject headings:
Darwin, Charles, 1809-1882--Ethics.
Ethics, Modern--20th century.
Freud, Sigmund, 1856-1939--Influence.
Marx, Karl, 1818-1883--Ethics.