The term heteroglossia describes the coexistence of distinct varieties within a single "language" (in Greek: hetero- "different" and glōssa "tongue, language"). The term translates the Russian разноречие [raznorechie: literally, "varied-speechedness"], which was introduced by the Russian literary theorist Mikhail Bakhtin in his 1934 paper Слово в романе [Slovo v romane], published in English as "Discourse in the Novel." For Bakhtin, this diversity of "languages" within a single language is not, in essence, a purely linguistic phenomenon: rather, heteroglossia is a reflection in language of varying ways of evaluating, conceptualizing and experiencing the world. It is the convergence in language or speech of "specific points of view on the world, forms for conceptualizing the world in words, specific world views, each characterized by its own objects, meanings and values."
Bakhtin viewed the modern novel as the literary form best suited to the exploitation of heteroglossia, in direct contrast to epic poetry (and, in a lesser degree, poetry in general). Bakhtin argues that the power of the novel originates in the coexistence of, and conflict between, different types of speech: the speech of characters, the speech of narrators, and even the speech of the author. He defines heteroglossia as "another's speech in another's language, serving to express authorial intentions but in a refracted way" (1934). Bakhtin identifies the direct narrative of the author, rather than dialogue between characters, as the primary location of this conflict.
Any language, in Bakhtin's view, stratifies into many voices: "social dialects, characteristic group behaviour, professional jargons, generic languages, languages of generations and age groups, tendentious languages, languages of the authorities, of various circles and of passing fashions". This diversity of voice is, Bakhtin asserts, the defining characteristic of the novel as a genre.
Traditional stylistics, like epic poetry, do not share the trait of heteroglossia. In Bakhtin's words, "poetry depersonalizes 'days' in language, while prose, as we shall see, often deliberately intensifies difference between them..."
Extending his argument, Bakhtin proposes that all languages represent a distinct point of view on the world, characterized by its own meaning and values. In this view, language is "shot through with intentions and accents" (1981: 324), and thus there are no neutral words. Even the most unremarkable statement possesses a taste, whether of a profession, a party, a generation, a place or a time. To Bakhtin, words do not exist until they are spoken, and in that moment they are imprinted with the signature of the speaker.
Bakhtin identifies the act of speech, or of writing, as a literary-verbal performance, one that requires speakers or authors to take a position, even if only by choosing the dialect in which they will speak. Separate languages are often identified with separate circumstances. Bakhtin gives an example of an illiterate peasant, who speaks Church Slavonic to God, speaks to his family in their own peculiar dialect, sings songs in yet a third, and attempts to emulate officious high-class dialect when he dictates petitions to the local government. The prose writer, Bakhtin argues, must welcome and incorporate these many languages into his work.
The hybrid utterance, as defined by Bakhtin, is a passage that employs only a single speaker—the author, for example— but uses different kinds of speech. The juxtaposition of the different speeches brings with it a contradiction and conflict in belief systems.
In examination of the English comic novel, particularly the works of Charles Dickens, Bakhtin identifies examples of his argument. Dickens parodies both the 'common tongue' and the language of Parliament or high-class banquets, using concealed languages to create humor. In one passage, Dickens shifts from his authorial narrative voice into a formalized, almost epic tone while describing the work of an unremarkable bureaucrat; his intent is to parody the self-importance and vainglory of the bureaucrat's position. The use of concealed speech, without formal markers of a speaker change, is what allows the parody to work. It is, in Bakhtin's parlance, a hybrid utterance. In this instance the conflict is between the factual narrative and the biting hyperbole of the new, epic/formalistic tone.
Bakhtin goes on to discuss the interconnectedness of conversation. Even a simple dialogue, in his view, is full of quotations and references, often to a general "everyone says" or "I heard that.." Opinion and information are transmitted by way of reference to an indefinite, general source. By way of these references, humans selectively assimilate the discourse of others and make it their own.
Bakhtin identifies a specific type of discourse, the "authoritative discourse," which demands to be assimilated by the reader or listener; examples might be religious dogma, or scientific theory, or a popular book. This type of discourse is viewed as past, finished, hierarchically superior, and therefore demands "unconditional allegiance" rather than accepting interpretation. Because of this, Bakhtin states that authoritative discourse plays an insignificant role in the novel. Because it is not open to interpretation, it cannot enter into hybrid utterance.
Bakhtin concludes by arguing that the role of the novel is to draw the authoritative into question, and to allow what was once considered certain to be debated and open to interpretation. In effect, novels not only function through heteroglossia, but must promote it; to do otherwise is an artistic failure.
Bakhtin's view of heteroglossia has been often employed in the context of the postmodern critique of the perceived teleological and authoritarian character of modernist art and culture. In particular, the latter's strong disdain for popular forms of art and literature—archetypically expressed in Adorno and Horkheimer's analysis of the culture industry—has been criticised as a proponent of monoglossia; practitioners of cultural studies have used Bakhtin's conceptual framework to theorise the critical reappropriation of mass-produced entertainment forms by the public.