The philosopher Aristotle wrote in his Poetics (c. 335 BC) that comedy is a representation of laughable people and involves some kind of blunder or ugliness which does not cause pain or disaster. C. A. Trypanis wrote that comedy is the last of the great species of poetry Greece gave to the world.
The Alexandrine grammarians, and most likely Aristophanes of Byzantium in particular, seem to have been the first to divide Greek comedy into what became the canonical three periods: Old Comedy (ἀρχαία archaia), Middle Comedy (μέση mese) and New Comedy (νέα nea). These divisions appear to be largely arbitrary, and ancient comedy almost certainly developed constantly over the years.
The most important Old Comic dramatist is Aristophanes. Born in 446 B.C., his works, with their pungent political satire and abundance of sexual and scatological innuendo, effectively define the genre today. Aristophanes lampooned the most important personalities and institutions of his day, as can be seen, for example, in his buffoonish portrayal of Socrates in The Clouds, and in his racy anti-war farce Lysistrata. He was one of a large number of comic poets working in Athens in the late 5th century, his most important contemporary rivals being Hermippus and Eupolis.
The Old Comedy subsequently influenced later European writers such as Rabelais, Cervantes, Swift, and Voltaire. In particular, they copied the technique of disguising a political attack as buffoonery.
The line between Old and Middle Comedy is not clearly marked chronologically, Aristophanes and others of the latest writers of the Old Comedy being sometimes regarded as the earliest Middle Comic poets. For ancient scholars, the term may have meant little more than "later than Aristophanes and his contemporaries, but earlier than Menander". Middle Comedy is generally seen as differing from Old Comedy in three essential particulars: the role of the chorus was diminished to the point where it had no influence on the plot; public characters were not impersonated or personified onstage; and the objects of ridicule were general rather than personal, literary rather than political. For at least a time, mythological burlesque was popular among the Middle Comic poets. Stock characters of all sorts also emerge: courtesans, parasites, revellers, philosophers, boastful soldiers, and especially the conceited cook with his parade of culinary science.