During the 1940s, moving from three different perspectives, the writings of Siegfried Kracauer, André Bazin and Sergei Eisenstein converged towards a common question: the question of identifying the "ursprüngliche Impulse" (Kracauer), the "urges," the "Triebe" (Eisenstein), and the "besoin fondamental" (Bazin) that could explain the appearance of cinema at the end of the 19th century and its main properties and tendencies as a medium.