Moving from a cinematic reinterpretation of Borges’s Library of Babel, I attempt to provide a new answer to the old ontological question: “What kind of being is a film?”. This answer, which takes into account the coming of digital era, is developed through a comparison with Carroll’s philosophy of motion pictures. While discussing, criticizing and trying to complete his theory, I will examine the concept of a film under four different aspects: as a material object, as an ideal object, as a mental object, and as a social object. Finally, our ontology of film will be applied to clarify some traditional theoretical dualisms: i.e. film vs. reality, film vs. narration, film vs. discourse, film vs. art.