Aristotle's Poetics is the earliest surviving work of Greek dramatic theory and the first extant philosophical treatise to solely focus on literary theory. In this text, Aristotle offers an account of ποιητική, which refers to poetry or, more literally, "the poetic art," deriving from the term for "poet, author, maker," ποιητής. Aristotle divides the art of poetry into verse, drama, lyric poetry, and epic poetry. The genres all share the function of mimesis, but differ in:Musical rhythm, harmony, meter, and melody; The goodness of the characters; and The mode of storytelling.