entousiasmos

Entousiasmos (Greek ένθουσιασμός) is a term commonly translated as enthusiasm, fervor, or zeal. The word derives from en- “in” and theos “god,” with the suffix -ismos forming a noun of state or action. Thus entousiasmos denotes a state of being inspired or possessed by a divine presence.

In ancient Greek religion and thought, entousiasmos referred to a form of ecstatic inspiration in which a person was believed to be temporarily inhabited by a deity. This inspiration could accompany prophecy, poetic composition, or ritual performance and was often described as a trance or revelatory experience. The concept is closely related to entheos, “in God,” and to the idea that a god could illuminate human creativity or insight.

Over time, the term acquired more secular meanings. In classical and postclassical Greek, entousiasmos came to denote ardor or ardent zeal in various pursuits. In Latin and later European languages, the word influenced the development of the term enthusiasm, which broadened from religiously tinged inspiration to describe intense interest or enthusiasm for a wide range of activities.

In modern usage, entousiasmos largely corresponds to the everyday sense of enthusiasm in Greek, though historical discussions of divine possession persist in studies of ancient religion and philosophy. The English word enthusiasm retains remnants of its original sense of divine inspiration, even as contemporary usage emphasizes spirited interest rather than literal possession.