Columbia subject headings:
Causation.
Leibniz, Gottfried Wilhelm, Freiherr von, 1646-1716.
Ontology.
Harvard subject headings:
Causation.
Contingency (Philosophy)
Existentialism.
Leibniz, Gottfried Wilhelm, Freiherr von, 1646-1716
Ontology.
Princeton subject headings:
Causation.
Leibniz, Gottfried Wilhelm, Freiherr von, 1646-1716.
Ontology.