This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book offers English readers, the first comprehensive introduction and preliminary study of Jean Epstein's movies, film theory, and literary and philosophical criticism in the age of cinema. It presents the many constituencies with which Epstein interacted over his lifetime: casual filmgoers, aficionados, researchers, teachers, students, historians, writers and artists, film archivists and museum curators, and movie industry professionals. The book looks at the foundational pair of books Epstein published in 1921-1922, amounting to a general critique of modernism in the new technological age, comparable to that of Walter Benjamin. It analyses the Brittany period of Epstein and his resolute embrace of a (pre-) neorealist documentarian ethos. The book explores his documentary production as a whole in its social and political advocacy of labour and workers' participation.