The present paper discusses Aristotle's "Poetics" in the light of one significant aspect of the Homeric innovation. Taking into account the given source and modern Homeric conceptions, the author of the paper classifies  the distinguishing criteria of the oral and written stages, which supposedly existed within the perennial process of the formation of the "Iliad". By way of illustration of the above-mentioned Book 9 of the "Iliad" is analyzed.