To Bakhtin, the novel stands apart from earlier forms such as the epic or lyric poem because it includes a multiplicity of voices. It is polyphonic, or made up of a blend of voices and dialects. It functions by including a number of different perspectives and clashing points of view. Therefore, Bakhtin characterized the novel as dialogic. In contrast, an epic like Homer's Iliad has a unifying worldview.

Bakhtin's theory of the novel came to the forefront in the late 1970s, when many groups such as women, blacks, formerly colonized peoples, and other minorities were fighting to articulate their views on literature and through literature. The idea that the novel was not a unified whole but actually derived its form and power by including conflicting, often subaltern (oppressed) viewpoints appealed very much to sensibilities of the time period—and it still does.

Bakhtin makes the important point in "Discourse in the Novel" that novels have to be approached as wholes. To slice and dice and take one character's perspective—even if that "character" is the narrator—as representative of a novel's worldview is to do violence to the genre.

The main thesis of "Discourse in the Novel" is that a novel's complexity lies in the combination of multiple forms, tropes, and references. Thus no novel stands alone, it is rather constructed in a social context. It includes the different types of narration by the author, oral narrative style, epistolary or letter-writing style, "the stylistically individualized speech of characters," and philosophical references. The novelist (and the readers of novels) arrange these references in ways that make the text comprehensible. So a novel is always, in a sense, in dialogue with other works, and the multiplicity of forms contained within it was "the basic distinguishing feature of the stylistics of the novel." This is a departure from some other critics who denied the novel had any artistic form at all.