Columbia subject headings:
Harvard subject headings:
Descartes, René, 1596-1650.
Leibniz, Gottfried Wilhelm, Freiherr von, 1646-1716
Philosophy, Modern--17th century.
Princeton subject headings:
Descartes, René, 1596-1650.
Leibniz, Gottfried Wilhelm, Freiherr von, 1646-1716.
Philosophy and science--History--17th century.
Philosophy, Modern--17th century.