Theory of Relations and Universal Harmony

This chapter discusses Gottfried Wilhelm Leibniz’s philosophical reflections on the theory of relations and universal harmony. It first describes the scholastic background on the doctrines concerning the ontology of relations before turning to Leibniz and his development of his theory of relations based on the ideas of Pierre Du Moulin and Caspar Bartholinus. More specifically, it examines Leibniz’s explicit characterization of the “mental” nature of relations using the Latin word concogitabilitas (co-thinkability), in which a relation arises when several things are thought of simultaneously. The article also considers Leibniz’s notions of the nature of relations “outside of the subjects,” relational predicates, relational properties and their foundations, and a class of predicates known as extrinsic denominations. Finally, it analyzes Leibniz’s idea of harmony and pre-established harmony.