In it, Aristotle offers an account of what he calls "poetry" (a term which in Greek literally means "making" and in this context includes drama - comedy, tragedy, and the satyr play - as well as lyric poetry and epic poetry). They are similar in the fact that they are all imitations but different in the three ways that Aristotle describes: 1. Differences in music rhythm, harmony, meter and melody. 2. Difference of goodness in the characters. 3. Difference in how the narrative is presented: telling a story or acting it out. In examining its "first principles," Aristotle finds two: 1) imitation and 2) genres and other concepts by which that of truth is applied/revealed in the poesis. His analysis of tragedy constitutes the core of the discussion. Although Aristotle's Poetics is universally acknowledged in the Western critical tradition, "almost every detail about his seminal work has aroused divergent opinions."

Theocritus (early third century BCE) was the inventor of the bucolic genre, also known as pastoral. The present edition of his work, along with that of his successors Moschus (fl. mid-second century BCE) and Bion (fl. around 100 BCE), replaces the earlier Loeb Classical Library volume of Greek Bucolic Poets by J. M. Edmonds (1912).