Documentaries-or whatever their directors care to call them-are just not my favorite kind of movie watching. The fact is I don't trust the little bastards. I don't trust the motives of those who think they are superior to fiction films. I don't trust their claim to have cornered the market on the truth. I don't trust their inordinately high, and entirely undeserved, status of bourgeois respectability.' -Marcel Ophuls Ophuls's ongoing career as a maker of serious documentaries belies his claim to mistrust the form. Nonetheless, Ophuls's declaration gets to the heart of what defines documentaries ("or whatever their directors care to call them"). All documentaries-whether they are deemed, in the end, to be reliable or notrevolve around questions of trust. A documentary is any motion picture that is susceptible to the question "Might it be lying?" It has been nearly seven decades since John Grierson first applied the term "documentary" to movies. Still, the definition of the term remains a vexed and controversial issue, not just among film theorists but also among people who make and watch documentaries. Definitions of genres like the western and film noir are in the last analysis fairly academic-of more concern to film scholars than to nonprofessional viewers. In contrast, as is apparent from the storms of controversy that rage around "fact-based" fiction films like JFK (1991) and Malcolm X (1992), the distinction between "fact" and "fiction" is a vital and important one to popular movie audiences. It is also probably indispensable in making sense of many kinds of everyday discourse, from dinner-table conversation to TV commercials. It is certainly crucial in the reception of discourses that are commonly regarded to be forms of nonfiction, including documentary. The question I wish to address in this article is, What difference does it make? How does it matter to the recipients of a discourse, in practical terms, whether the discourse is considered to be fiction or nonfiction? Although I will focus chiefly on documentary here-that is, on movies that are supposed to be nonfiction2-this question pertains to other forms of nonfiction as well, such as history and journalism. Documentary has been variously defined through the years as "a dramatized presentation of man's relation to his institutional life," as "film with a message," as "the communication, not of imagined things, but of real things only," and as films