Without Aristotle’s Rhetoric written down, and making speech sound like writing, we would not have understood each other. We would have made sounds that made sense to us, like animals, and not have been able to interpret each others noises. We have to come to an understanding of each other through the artful or skill skillful use of writing. Writing organizes thought.

Aristotle’s Art of Rhetoric – https://ryanfb.github.io/loebolus-data/L193.pdf

“Once you have experienced this kind of orderly organization of thought, you could talk “that way” a little bit [emphasis on observation] – you could make your talk sound a little bit like writing. Because you’ve heard that, you knew what it was like. And you better do it or you won’t get along in the world. If you couldn’t make your talk sound like writing you weren’t educated – and if you couldn’t make it sound like writing you couldn’t really think. In the advanced kind of way that writing made it necessary to think – in this scientific kind of way. The new medium, writing, has re-enforced the old. It’s made talkers talk more; but it has made them talk differently. And that’s always what happens when a new medium comes in, it never wipes out the old, but it always re-enforces it. But it changes it, so that it no longer does what it used to do the same way, so you have to know the new medium or you can’t use the old. The same thing happened with print…”

More on Ong on the differences between orality and literacy