Columbia subject headings:
Goethe, Johann Wolfgang von, 1749-1832.
Leibniz, Gottfried Wilhelm, Freiherr von, 1646-1716.
Harvard subject headings:
Goethe, Johann Wolfgang von, 1749-1832
Leibniz, Gottfried Wilhelm, Freiherr von, 1646-1716
Princeton subject headings:
Goethe, Johann Wolfgang von, 1749-1832--Knowledge--Natural history.
Leibniz, Gottfried Wilhelm, Freiherr von, 1646-1716.
Philosophy of nature.
Substance (Philosophy)