The animal-machine:New ideas on animals in early modern philosophy and science

This dissertation examines seventeenth-century conceptions of animals through comparative analysis of five mechanist philosophers: Descartes, Gassendi, Hobbes, Spinoza, and Leibniz. Given their shared commitment to mechanistic explanations of natural phenomena and collective rejection of Scholastic substantial forms, one would expect these thinkers to reach similar conclusions about animal nature, particularly endorsing the Cartesian "bête-machine" doctrine that animals are automata devoid of sensation and consciousness. Through systematic examination of each philosopher's experimental work, epistemology, scientific principles, and views on human-animal distinctions, the thesis demonstrates that this expected uniformity did not materialize. Rather than mechanism itself determining these philosophers' positions on animals, their collective opposition to Cartesian doctrine served as the organizing principle. Gassendi, Hobbes, Spinoza, and Leibniz, despite sharing mechanistic frameworks, maintained that animals possess genuine sensory experience, perception, and varying degrees of sentience. The analysis reveals that specific Cartesian commitments generated the restrictive view that denied animal experience. Leibniz's retention of substantial forms, uniquely among these mechanists, enabled a particularly rich account of animal life within his mechanistic framework. The dissertation demonstrates that divergent philosophical systems, rather than shared scientific methodology, determined positions on animal minds. This finding contributes to early modern intellectual history and illuminates how theoretical commitments beyond empirical observation shape conclusions about non-human experience.