Theaetetus

THEO. Certainly not.

SOC. And does it always hit the mark, or does every state often miss it?

THEO. I should say they do often miss it!

SOC. Continuing, then, and proceeding from this point, every one would more readily agree to this assertion, if the question were asked concerning the whole class to which the advantageous belongs; and that whole class, it would seem, pertains to the future. For when we make laws, we make them with the idea that they will be advantageous in after time; and this is rightly called the future.

THEO. Certainly.

SOC. Come then, on this assumption, let us question Protagoras or someone of those who agree with him. Man is the measure of all things, as your school says, Protagoras, of the white, the heavy, the light, everything of that sort without exception; for he possesses within himself the standard by which to judge them, and when his thoughts about them coincide with his sensations, he thinks what to him is true and really is. Is not that what they say?

THEO. Yes.

SOC. Does he, then, also, Protagoras, we shall say, possess within himself the standard by which to judge of the things which are yet to be, and do those things which he thinks will be actually come to pass for him who thought them? Take, for instance, heat; if some ordinary man thinks he is going to take a fever, that is to say, that this particular heat will be, and some other man, who is a physician, thinks the contrary, whose opinion shall we expect the future to prove right? Or perhaps the opinion of both, and the man will become, not hot or feverish to the physician, but to himself both?

THEO. No, that would be ridiculous.

SOC. But, I imagine, in regard to the sweetness or dryness which will be in a wine, the opinion of the husbandman, not that of the lyre-player, will be valid.

THEO. Of course.

SOC. And again, in a matter of discord or tunefulness in music that has never been played, a gymnastic teacher could not judge better than a musician what will, when performed, seem tuneful even to a gymnastic teacher himself.

THEO. Certainly not.

SOC. Then, too, when a banquet is in preparation the opinion of him who is to be a guest, unless he has training in cookery, is of less value concerning the pleasure that will be derived from the viands than that of the cook. For we need not yet argue about that which already is or has been pleasant to each one but concerning that which will in the future seem and be pleasant to each one, is he himself the best judge for himself, or would you, Protagoras—at least as regards the arguments which will be persuasive in court to each of us—be able to give an opinion beforehand better than anyone whatsoever who has no especial training?

THEO. Certainly, Socrates, in this, at any rate, he used to declare emphatically that he himself excelled everyone.

SOC. Yes, my friend, he certainly did; otherwise nobody would have paid him a high fee for his conversations, if he had not made his pupils believe that neither a prophet nor anyone else could judge better than himself what was in the future to be and seem.

THEO. Very true.

SOC. Both lawmaking, then, and the advantageous are concerned with the future, and everyone would agree that a state in making laws must often fail to attain the greatest advantage?

THEO. Assuredly.

SOC. Then it will be a fair answer if we say to your master that he is obliged to agree that one man is wiser than another, and that such a wise man is a measure, but that I, who am without knowledge, am not in the least obliged to become a measure, as the argument in his behalf just now tried to oblige me to be, whether I would or no.

THEO. In that respect, Socrates, I think that the argument is most clearly proved to be wrong, and it is proved wrong in this also, in that it declares the opinions of others to be valid, whereas it was shown that they do not consider his arguments true at all.

SOC. In many other respects, Theodorus, it could be proved that not every opinion of every person is true, at any rate in matters of that kind; but it is more difficult to prove that opinions are not true in regard to the momentary states of feeling of each person, from which our perceptions and the opinions concerning them arise. But perhaps I am quite wrong; for it may be impossible to prove that they are not true, and those who say that they are manifest and are forms of knowledge may perhaps be right, and Theaetetus here was not far from the mark in saying that perception and knowledge are identical. So we must, as the argument in behalf of Protagoras [*](See 168 B.) enjoined upon us, come up closer and examine this doctrine of motion as the fundamental essence, rapping on it to see whether it rings sound or unsound. As you know, a strife has arisen about it, no mean one, either, and waged by not a few combatants.

THEO. Yes, far from mean, and it is spreading far and wide all over Ionia; for the disciples of Heracleitus are supporting this doctrine very vigorously.

SOC. Therefore, my dear Theodorus, we must all the more examine it from the beginning as they themselves present it.

THEO. Certainly we must. For it is no more possible, Socrates, to discuss these doctrines of Heracleitus (or, as you say, of Homer or even earlier sages) with the Ephesians themselves—those, at least, who profess to be familiar with them—than with madmen. For they are, quite in accordance with their text-books, in perpetual motion; but as for keeping to an argument or a question and quietly answering and asking in turn, their power of doing that is less than nothing; or rather the words nothing at all fail to express the absence from these fellows of even the slightest particle of rest. But if you ask one of them a question, he pulls out puzzling little phrases, like arrows from a quiver, and shoots them off; and if you try to get hold of an explanation of what he has said, you will be struck with another phrase of novel and distorted wording, and you never make any progress whatsoever with any of them, nor do they themselves with one another, for that matter, but they take very good care to allow nothing to be settled either in an argument or in their own minds, thinking, I suppose, that this is being stationary; but they wage bitter war against the stationary, and, so far as they can, they banish it altogether.

SOC. Perhaps, Theodorus, you have seen the men when they are fighting, but have not been with them when they are at peace; for they are no friends of yours; but I fancy they utter such peaceful doctrines at leisure to those pupils whom they wish to make like themselves.

THEO. What pupils, my good man? Such people do not become pupils of one another, but they grow up of themselves, each one getting his inspiration from any chance source, and each thinks the other knows nothing. From these people, then, as I was going to say, you would never get an argument either with their will or against it; but we must ourselves take over the question and investigate it as if it were a problem of mathematics.

SOC. Yes, what you say is reasonable. Now as for the problem, have we not heard from the ancients, who concealed their meaning from the multitude by their poetry, that the origin of all things is Oceanus and Tethys, flowing streams, and that nothing is at rest and likewise from the modern, who, since they are wiser, declare their meaning openly, in order that even cobblers may hear and know their wisdom and may cease from the silly belief that some things are at rest and others in motion, and, after learning that everything is in motion, may honor their teachers? But, Theodorus, I almost forgot that others teach the opposite of this,

1. So that it is motionless, the name of which is the All,