[mattdeboard]

Cave drawings throughout the American southwest demonstrate Native Americans of antiquity were just as capable of expressing symbolic thought via a durable medium to express meaning to other humans as so-called modern humans.

I know I'm arguably moving the goalposts here from "writing stuff down for others to read" to "using symbols on a durable medium to express meaning to other humans." But that's a category of behavior that writing belongs to so I don't think it's logically inconsistent. :)