Plato seems to have been convinced that writing could never be a sufficient vehicle for communicating knowledge directly. Writing can only convey doxa/opinion, never the truth of the matter. This is one of the reasons that Plato requires a defective reading, since a text must testify to its defects in order to be true about its own falseness. What follows is a long quote from the Phaedrus dialogue on this theme:
Plato’s Phaedrus (from Plato in Twelve Volumes, Vol. 9, translated by Harold N. Fowler. Cambridge, MA, Harvard University Press; London, William Heinemann Ltd. 1925. http://www.perseus.tufts.edu)
Socrates.[274c]
I heard, then, that at Naucratis, in Egypt, was one of the ancient gods of that country, the one whose sacred bird is called the ibis, and the name of the god himself was Theuth. He it was who [274d] invented numbers and arithmetic and geometry and astronomy, also draughts and dice, and, most important of all, letters. Now the king of all Egypt at that time was the god Thamus, who lived in the great city of the upper region, which the Greeks call the Egyptian Thebes, and they call the god himselfAmmon. To him came Theuth to show his inventions, saying that they ought to be imparted to the other Egyptians. But Thamus asked what use there was in each, and as Theuth enumerated their uses, expressed praise or blame, according as he approved [274e] or disapproved. The story goes that Thamus said many things to Theuth in praise or blame of the various arts, which it would take too long to repeat; but when they came to the letters, “This invention, O king,” said Theuth, “will make the Egyptianswiser and will improve their memories; for it is an elixir of memory and wisdom that I have discovered.” But Thamus replied, “Most ingenious Theuth, one man has the ability to beget arts, but the ability to judge of their usefulness or harmfulness to their users belongs to another; [275a] and now you, who are the father of letters, have been led by your affection to ascribe to them a power the opposite of that which they really possess. 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.
Phaedrus
Socrates, you easily make up stories of Egypt or any country you please.
Socrates
They used to say, my friend, that the words of the oak in the holy place of Zeus at Dodona were the first prophetic utterances. The people of that time, not being so wise as you young folks, were content in their simplicity to hear an oak 275c] or a rock, provided only it spoke the truth; but to you, perhaps, it makes a difference who the speaker is and where he comes from, for you do not consider only whether his words are true or not.
Phaedrus
Your rebuke is just; and I think the Theban is right in what he says about letters.
Socrates
He who thinks, then, that he has left behind him any art in writing, and he who receives it in the belief that anything in writing will be clear and certain, would be an utterly simple person, and in truth ignorant of the prophecy of Ammon, if he thinks [275d] written words are of any use except to remind him who knows the matter about which they are written.
Phaedrus
Very true.
Socrates
Writing, Phaedrus, has this strange quality, and is very like painting; for the creatures of painting stand like living beings, but if one asks them a question, they preserve a solemn silence. And so it is with written words; you might think they spoke as if they had intelligence, but if you question them, wishing to know about their sayings, they always say only one and the same thing. And every word, when [275e] once it is written, is bandied about, alike among those who understand and those who have no interest in it, and it knows not to whom to speak or not to speak; when ill-treated or unjustly reviled it always needs its father to help it; for it has no power to protect or help itself.
Phaedrus
You are quite right about that, too.
[276a] Socrates
Now tell me; is there not another kind of speech, or word, which shows itself to be the legitimate brother of this bastard one, both in the manner of its begetting and in its better and more powerful nature?
Phaedrus
What is this word and how is it begotten, as you say?
Socrates
The word which is written with intelligence in the mind of the learner, which is able to defend itself and knows to whom it should speak, and before whom to be silent.
Phaedrus
You mean the living and breathing word of him who knows, of which the written word may justly be called the image.
[276b] Socrates
Exactly. Now tell me this. Would a sensible husbandman, who has seeds which he cares for and which he wishes to bear fruit, plant them with serious purpose in the heat of summer in some garden of Adonis, and delight in seeing them appear in beauty in eight days, or would he do that sort of thing, when he did it at all, only in play and for amusement? Would he not, when he was in earnest, follow the rules of husbandry, plant his seeds in fitting ground, and be pleased when those which he had sowed reached their perfection in the eighth month?
[276c] Phaedrus
Yes, Socrates, he would, as you say, act in that way when in earnest and in the other way only for amusement.
Socrates
And shall we suppose that he who has knowledge of the just and the good and beautiful has less sense about his seeds than the husbandman?
Phaedrus
By no means.
Socrates
Then he will not, when in earnest, write them in ink, sowing them through a pen with words which cannot defend themselves by argument and cannot teach the truth effectually.
Phaedrus
No, at least, probably not.
[276d] Socrates
No. The gardens of letters he will, it seems, plant for amusement, and will write, when he writes, to treasure up reminders for himself, when he comes to the forgetfulness of old age, and for others who follow the same path, and he will be pleased when he sees them putting forth tender leaves. When others engage in other amusements, refreshing themselves with banquets and kindred entertainments, he will pass the time in such pleasures as I have suggested.
[276e] Phaedrus
A noble pastime, Socrates, and a contrast to those base pleasures, the pastime of the man who can find amusement in discourse, telling stories about justice, and the other subjects of which you speak.
Socrates
Yes, Phaedrus, so it is; but, in my opinion, serious discourse about them is far nobler, when one employs the dialectic method and plants and sows in a fitting soul intelligent words which are able to help themselves and him [277a] who planted them, which are not fruitless, but yield seed from which there spring up in other minds other words capable of continuing the process for ever, and which make their possessor happy, to the farthest possible limit of human happiness.
Phaedrus
Yes, that is far nobler.
Socrates
And now, Phaedrus, since we have agreed about these matters, we can decide the others.
Phaedrus
What others?
Socrates
Those which brought us to this point [277b] through our desire to investigate them, for we wished to examine into the reproach against Lysias as a speechwriter,See Plat. Phaedrus 257c. and also to discuss the speeches themselves and see which were the products of art and which were not. I think we have shown pretty clearly what is and what is not a work of art.
Phaedrus
Yes, I thought so, too; but please recall to my mind what was said.
Socrates
A man must know the truth about all the particular things of which he speaks or writes, and must be able to define everything separately; then when he has defined them, he must know how to divide them by classes until further division is impossible; and in the same way he must understand the nature of the soul, [277c] must find out the class of speech adapted to each nature, and must arrange and adorn his discourse accordingly, offering to the complex soul elaborate and harmonious discourses, and simple talks to the simple soul. Until he has attained to all this, he will not be able to speak by the method of art, so far as speech can be controlled by method, either for purposes of instruction or of persuasion. This has been taught by our whole preceding discussion.
Phaedrus
Yes, certainly, that is just about our result.
Socrates
How about the question whether it is a fine or a disgraceful thing to be a speaker or writer 277d] and under what circumstances the profession might properly be called a disgrace or not? Was that made clear a little while ago when we said–
Phaedrus
What?
Socrates
That if Lysias or anyone else ever wrote or ever shall write, in private, or in public as lawgiver, a political document, and in writing it believes that it possesses great certainty and clearness, then it is a disgrace to the writer, whether anyone says so, or not. For whether one be awake or asleep, ignorance of right and wrong and good and bad [277e] is in truth inevitably a disgrace, even if the whole mob applaud it.
Phaedrus
That is true.
Socrates
But the man who thinks that in the written word there is necessarily much that is playful, and that no written discourse, whether in meter or in prose, deserves to be treated very seriously (and this applies also to the recitations of the rhapsodes, delivered to sway people’s minds, without opportunity for questioning and teaching), [278a] but that the best of them really serve only to remind us of what we know; and who thinks that only in words about justice and beauty and goodness spoken by teachers for the sake of instruction and really written in a soul is clearness and perfection and serious value, that such words should be considered the speaker’s own legitimate offspring, first the word within himself, if it be found there, and secondly [278b] its descendants or brothers which may have sprung up in worthy manner in the souls of others, and who pays no attention to the other words,–that man, Phaedrus, is likely to be such as you and I might pray that we ourselves may become.
Phaedrus
By all means that is what I wish and pray for.
Socrates
We have amused ourselves with talk about words long enough. Go and tell Lysias that you and I came down to the fountain and sacred place of the nymphs, [278c] and heard words which they told us to repeat to Lysias and anyone else who composed speeches, and to Homer or any other who has composed poetry with or without musical accompaniment, and third to Solon and whoever has written political compositions which he calls laws: If he has composed his writings with knowledge of the truth, and is able to support them by discussion of that which he has written, and has the power to show by his own speech that the written words are of little worth, such a man ought not [278d] to derive his title from such writings, but from the serious pursuit which underlies them.
Phaedrus
What titles do you grant them then?
Socrates
I think, Phaedrus, that the epithet “wise” is too great and befits God alone; but the name “philosopher,” that is, “lover of wisdom,” or something of the sort would be more fitting and modest for such a man.
shared ignorance 