Columbia subject headings:
Ethics--Austria--Vienna--20th century.
Philosophy, Austrian--20th century.
Vienna circle.
Harvard subject headings:
Ethics--Austria--Vienna--20th century.
Humanism--Austria--Vienna--History--20th century.
Philosophy, Austrian--20th century.
Vienna circle.
Princeton subject headings:
Ethics--Austria--Vienna--20th century.
Philosophy, Austrian--20th century.
Vienna circle.