According to Aristotle, poetry originated in the human soul from the “instinct of imitation” and “harmony.”
First, the instinct of imitation is implanted in man from childhood, one difference between him and other animals being that he is the most imitative of living creatures, and through imitation learns his earliest lessons… (Part 1).
Humans love to see things reproduced to the most minor detail, so it makes sense that we would develop forms of art that are imitation.
Aristotle argued that second of all, poetry springs from our need for harmony.
Next, there is the instinct for 'harmony' and rhythm, meters being manifestly sections of rhythm. (Part 1).
People love music, and singing, and rhythm, so we incorporate these into our poetry.
Aristotle argued that tragedy started as improvisation. He explains that plays actually started from people improvising in singing and story-telling.
Tragedy- as also Comedy- was at first mere improvisation. The one originated with the authors of the Dithyramb, the other with those of the phallic songs, which are still in use in many of our cities. (Part 4)
Aristotle’s argument is that people shared their culture by story-telling, but then it developed into plays. Improvisation is making things up on the spot. When something is improvised, it is performed a little differently every time. For example, a singer might go from village to village singing a story, but change the story based on reactions of the audience.
Tragedy and Comedy have similar origins, according to Aristotle.
The claim to Comedy is put forward by the Megarians- not only by those of Greece proper, who allege that it originated under their democracy, but also by the Megarians of Sicily, for the poet Epicharmus… (Part 3)
Democracy would have been more of a testing ground for poetry, because Aristotle maintains politics and poetry go together.