I need a critical account of Aristotle's view of poetry as an art form.

Aristotle's main work about poetry is his Poetics. In this work, he attempts to explain the nature of poetry and how it functions in the polis. He divides poetry into two main types, epic and dramatic. Both genres are essentially narrative, and use meter, but proceed by different formal structures. Dramatic verse consists purely of mimesisor imitation of action, in which actors perform on a stage imitating the characters portrayed. Epic is a...

Aristotle's main work about poetry is his Poetics. In this work, he attempts to explain the nature of poetry and how it functions in the polis. He divides poetry into two main types, epic and dramatic. Both genres are essentially narrative, and use meter, but proceed by different formal structures. Dramatic verse consists purely of mimesis or imitation of action, in which actors perform on a stage imitating the characters portrayed. Epic is a mixed genre that includes mimesis (the rhapsode reciting the epic imitating dialogue) and diegesis or narration (in which the rhapsode narrates the events in the third person). Drama is divided into two types, comedy, which makes fun of ignoble characters, and tragedy which evokes fear and pity by portraying the fall of noble characters. 

While Plato believed that most forms of poetry harmed the polis, Aristotle viewed poetry in a more positive light, believing that it helped people achieve catharsis (purgation) of emotions by means of feeling fear and pity at the spectacle before them. 

While Aristotle's account of poetry has been enormously influential, critics do argue that it is limited by Aristotle's ignorance of literary forms other than those used in classical Greece and his tendency to universalize conclusions drawn from a limited set of evidence.