The Author attempts to reconstruct Leibniz’s philosophy through the physiology of the processes of perception, inner sense, and general cognition, and their metaphysical implications, using both Leibniz’s published and unpublished works. The volume contains four chapters ("The Young Leibniz", "Thought Mechanisms", "The Means of Perception", "The Functions of Imagination"), and a number of hitherto unpublished texts by Leibniz.