Abstract

This dissertation originates from the problem suggested by the view that Leibniz is an idealist whose theory of preestablished harmony purports to solve a problem of dualism: incommunication between body and mind. It is an inquiry into the meaning of "preestablished harmony" and "corporeal substance," aimed at obtaining a definite answer to the question, Is Leibniz an idealist? ;Our historical approach to "preestablished harmony" suggests a basic affinity between Leibniz and Malebranche, manifested in their rejection of Descartes's causal account of the mind-body relation and the recognition that concomitance between mind and body occurrences requires another explanation. Leibniz's insatisfaction with occasionalism is examined as indicative of: his rejection of philosophies which disregard "essences" as explanatory principles; his acceptance of mechanicism and rejection of materialism, on the basis of hylemorphism; his conception of metaphysics as the elucidation of the consequences for creation of God's nature. ;The features of Leibniz's philosophy that suggests a dualist interpretation are contrasted with those which seem favorable to idealism. The question about the origin of the problem of incommunication between body and mind is treated as crucial to this issue, as either metaphysical incommensurability between body and mind excludes interaction, or the "substantial spontaneity" which originates from Leibniz's conception of truth seem its basis. ;Leibniz's conception of corporeal substance is examined, initially in the context of the Discourse and the Correspondence with Arnauld in order to refute Stuart Brown's idealistic interpretation. Leibniz's dynamics, his hylemorphic conception of corporeal substance, and his account of bodies as aggregates are presented as evidence that he asserts the existence of corporeal substances. His mature views on dynamics and his conception of transubstantiation prove confirmatory of this interpretation. ;Finally, the significance of "essentialism" and "hylemorphism" are stressed as crucial to Leibniz's thinking. Essentialism is the basis of Leibniz's methodological outlook. Hylemorphism is Leibniz's basic ontological notion. It enables him to profess a non-Cartesian type of dualism and to avoid the defects of Scholasticism and excesses of the moderns. The dissertation concludes by establishing that preestablished harmony conflicts with hylemorphism, and that there are inconsistencies in Leibniz's treatment of substantial form and matter