A well-established, well-defined art is characterized by its practitioners, its own history, and its own body of formal criticism;at its highest reaches, it will command philosophic attention. Film has its artists, its historians, its critics-although, save for suggested applications of structural semiotics, it would be as yet difficult to claim a formal and consistent organization for film theory or film criticism. As an art, a full-blown, unquestioned art form, however, film's status is notably tenuous, sometimes embarrassing, always confusing. The considerable and insistent semiotic activity devoted to film, the amount of literature now available in this area, and the fact that linguistic study is very much a part of contemporary philosophy appear to compel at least sporadic philosophic examination. The ambiguity of film's aesthetic value is no better revealed than in these occasional plunges by professional aestheticians. There is a sense of discomfort in these forays, and not without reason. Four major obstacles seem to stand in the way of film's being easily accepted as an undoubted art form in the same manner the other arts are: