Columbia subject headings:
Descartes, René, 1596-1650.
Leibniz, Gottfried Wilhelm, Freiherr von, 1646-1716.
Spinoza, Benedictus de, 1632-1677.
Harvard subject headings:
Descartes, René, 1596-1650.
Leibniz, Gottfried Wilhelm, Freiherr von, 1646-1716
Spinoza, Benedictus de, 1632-1677
Princeton subject headings: