Columbia subject headings:
Evolution--History--19th century--Congresses.
Intellectual life--History--19th century--Congresses.
Materialism--History--19th century--Congresses.
Philosophy and science--History--19th century--Congresses.
Skepticism--History--19th century--Congresses.
Harvard subject headings:
Evolution--History--19th century--Congresses.
Intellectual life--History--19th century--Congresses.
Materialism--History--19th century--Congresses.
Philosophy and science--History--19th century--Congresses.
Skepticism--History--19th century--Congresses.
Princeton subject headings:
Materialism--History--19th century--Congresses.
Science--Philosophy--History--19th century--Congresses.