Writing had existed for 3000 years by then, alphabetic writing in Greek had existed for several centuries. The quote about "the invention of writing" is Socrate

Writing had existed for 3000 years by then, alphabetic writing in Greek had existed for several centuries. The quote about "the invention of writing" is Socrates telling a story where a mythical Egyptian king says that. Socrates also says in this dialogue: "Any one may see that there is no disgrace in the mere fact of writing." The essence of his admonishment is that having access to written text is not enough to produce understanding, and I not only tend to agree, I think it is more relevant than ever now.