may also be used as a wider term covering genre painting proper, and other specialized types of paintings such as still-life, landscapes, marine paintings and animal paintings. The concept of the "hierarchy of genres" was a powerful one in artistic theory, especially between the 17th and 19th centuries. It was strongest in France, where it was associated with the Académie française which held a central role in academic art. The genres in hierarchical order are: History painting, including narrative, religious, mythological and allegorical subjects Portrait painting Genre painting or scenes of everyday life Landscape (landscapists were the "common footmen in the Army of Art" according to the Dutch theorist Samuel van Hoogstraten) and cityscape Animal painting Still life Literature A literary genre is a category of literary composition. Genres may be determined by literary technique, tone, content, or even (as in the case of fiction) length. Genre should not be confused with age category, by which literature may be classified as either adult, young adult, or children's. They also must not be confused with format, such as graphic novel or picture book. The distinctions between genres and categories are flexible and loosely defined, often with subgroups. The most general genres in literature are (in loose chronological order) epic, tragedy, comedy, novel, and short story. They can all be in the genres prose or poetry, which shows best how loosely genres are defined. Additionally, a genre such as satire might appear in any of the above, not only as a subgenre but as a mixture of genres. Finally, they are defined by the general cultural movement of the historical period in which they were composed. In popular fiction, which is especially divided by genres, genre fiction is the more usual term. In literature, genre has been known as an intangible taxonomy. This taxonomy implies a concept of containment or that an idea will be stable forever. The earliest recorded systems of genre in Western history can be traced back to Plato and Aristotle. Gérard Genette, a French literary theorist and author of The Architext, describes Plato as creating three Imitational genres: dramatic dialogue, pure narrative, and epic (a mixture of dialogue and narrative). Lyric poetry, the fourth and final type of Greek literature, was excluded by Plato as a non-mimetic mode. Aristotle later revised Plato's system by eliminating the pure narrative as a viable mode and distinguishing by two additional criteria: