Bazin was a major force in post-World War II film studies and criticism. In addition to editing
Cahiers until his death, a four-volume collection of his writings was published posthumously from 1958 to 1962 and titled
Qu'est-ce que le cinéma? (
What is Cinema?). Two of these volumes were translated into English in the late 1960s and 1970s and became mainstays of film courses in the US and England.
Bazin argued for films that depicted what he saw as "objective reality" (such as documentaries and films of the
Italian neorealism school) and directors who made themselves "invisible" (such as
Howard Hawks). He advocated the use of
deep focus (
Orson Welles), wide shots (
Jean Renoir) and the "shot-in-depth", and preferred what he referred to as "true continuity" through
mise en scène over experiments in editing and visual effects. This placed him in opposition to film theory of the 1920s and 1930s which emphasized how the cinema can manipulate reality. The concentration on objective reality, deep focus, and lack of
montage are linked to Bazin's belief that the interpretation of a film or scene should be left to the spectator.
Bazin believed that a film should represent a director's personal vision, which was rooted in the spiritual beliefs known as
personalism. These ideas would have a pivotal importance on the development of the
Auteur theory, which originated in an article by Truffaut in
Cahiers. Bazin also is known as a proponent of "appreciative criticism," wherein only critics who like a film can write a review of it, thus encouraging constructive criticism.