Stream of consciousness is a narrative device used in literature "to depict the multitudinous thoughts and feelings which pass through the mind. Another phrase for it is 'interior monologue'." The term "Stream of Consciousness" was coined by philosopher and psychologist William James in The Principles of Psychology (1890):In literary criticism, stream of consciousness is a narrative mode that seeks to portray an individual's point of view by giving the written equivalent of the character's thought processes, either in a loose interior monologue (see below), or in connection to his or her actions. Stream-of-consciousness writing is usually regarded as a special form of interior monologue and is characterized by associative leaps in thought and lack of punctuation. Stream of consciousness and interior monologue are distinguished from dramatic monologue and soliloquy, where the speaker is addressing an audience or a third person, which are chiefly used in poetry or drama. In stream of consciousness the speaker's thought processes are more often depicted as overheard in the mind (or addressed to oneself); it is primarily a fictional device.

In the following example of stream of consciousness from James Joyce's Ulysses, Molly seeks sleep: