The aim of this paper is to show that the doctrine of animal spirits plays an important role in the philosophy of the Marquis Donatien-Alphonse-François de Sade, especially in his theory of passions. Sade consciously modifies the notion of animal spirits in relation to the early modern tradition, turning this notion into an "electrical materialism". The idea of energy applied to animal spirits eliminates the Cartesian dualism, allowing the construction of new links between psychic life and physiological mechanisms. This electrical conception of animal spirits is useful for a better understanding of the relation between the physical and the moral dimensions that characterizes the new anthropological model endorsed by Sade, the libertine. The "divine Marquis" opposes to the Cartesian rejection of passions an original form of "passionate stoicism". Emotional restraint, generally regarded as the ultimate goal of spiritual wisdom, becomes in fact the instrument for achieving the full expression - egoic and terrestrial - of the passions.
Keywords: Sade, animal spirits, nerves, electricity, stoicism, passions, apathy