"For this invention will produce forgetfulness in the minds of those who learn to use it, because they will not practice their memory. Their trust in writing, produced by external characters which are no part of themselves, will discourage the use of their own memory within them. You have invented an elixir not of memory, but of reminding; and you offer your pupils the appearance of wisdom, not true wisdom, for they will read many things without instruction and will therefore seem [275b] to know many things, when they are for the most part ignorant and hard to get along with, since they are not wise, but only appear wise."
That is a fictional objection raised by the Egyptian god Amun to the Egyptian god Thoth, who was supposed by the Egyptians to have invented music and writing, and was supposed by the Greeks to have invented absolutely everything else too, including botany, surveying, and government.
It's also a critique of writing, written by Plato, to impress on us that Socrates was great orator (or arguer) and was better that way. But it's not somebody's reaction to the invention of writing. It's an imagined reaction to the invention of writing.
Be wonderful if you approached a translated piece, by first considering the time and culture that produced it. Understanding the intent, rather than quoting it out of place.
This is a political critique, on the rule of law (writing) over attempting to treat things on a case by case basis (philosophy).
Quoting it, without understanding it, is part of that author's complaint.
