Denis Diderot was one of the most important thinkers of the French Enlightenment, and the recent scholarly consensus attributes the practice of presenting marionettes as role models for actors goes back to Diderot. This author argues that the existing scholarship comparing Diderot’s acting treatise to theories of the historical avant-garde have led to a one-sided view of his mannequin metaphor as an artist’s tool, and the material conditions in which it was situated in the eighteenth century. Therefore this volume seeks to demonstrate that a deep dive into eighteenth-century material culture is necessary to fully do justice to Diderot’s acting theory through the examination of the intersection of eighteenth-century theories of acting and material culture. This is in order to open new perspectives on Diderot’s mannequin metaphor and related metaphors of humanoid objects.