The Soul as Spiritual Automaton in Leibniz's Synthetic Natural Philosophy

This dissertation is a study Gottfried Wilhelm Leibniz's repeated characterization of the soul as a "spiritual" or "incorporeal" automaton. Within Leibniz's mature period philosophy of nature, souls play a necessary metaphysical role in providing unity and activity to bodies. I situate Leibniz's use of the term "automaton" within the wider philosophical context of seventeenth and early eighteenth-century Europe and explain why it provides a useful model to capture the operation of the soul. I argue that for Leibniz, souls are like automata in three ways: they act spontaneously according to an internal principle of motion; they act in a way that depends upon their design by God; they move themselves without the need for conscious thought or deliberation. In comparing the soul to a "spiritual automaton," Leibniz combines the traditional notion of an immaterial soul with that of a self-moving mechanical device. I therefore argue that the concept of the soul as a "spiritual automaton" embodies Leibniz's synthetic or conciliatory approach to philosophy, which seeks to harmonize elements from seemingly divergent intellectual positions. Accordingly, I connect Leibniz's development of the concept of the soul as spiritual automaton to his his critical appropriation of elements of the mechanical philosophy of Hobbes and Descartes and his intellectual engagement with Spinoza. Further, I show how Leibniz deploys the concept as a means to resolve philosophical controversies regarding the mode of activity of immaterial substances involving Ralph Cudworth, Jean Le Clerc, Isaac Jaquelot, and Pierre Bayle.