Theae. Manifestly.

So. In the name of the Graces, then, was Protagoras a man of consummate shrewdness, and did he hint this darkly to us of the common herd, while to his disciples he spoke 'the truth' in secret confidence1?

Theae. What do you mean by this, Socrates?

So. I will state to you a doctrine of no slight importance: namely, that nothing in itself 'is one,' nor can you rightly call a thing 'some' or 'of some kind,' but, if you style it great, it will turn out also small, and if heavy, light, and so in every case; since nothing 'is' 'one' or 'some,' or 'of some kind': but from vection and motion and mixture with each other all things come to be,' of which we say that they are,' using a wrong term: for nothing at any time 'is,' but always 'comes to be.' And on this point let all philosophers except Parmenides be compared in their order, Protagoras and Heracleitus and Empedocles: and of the poets those that are consummate in each poetic kind,

5

4 The work in which Protagoras expounded his doctrine was called 'Anoia, Truth. To this circumstance Plato here alludes, but perhaps, as Prof. Campbell says, he means that Protagoras “told the real truth, not in his book which is so entitled, but privately to his disciples."

5 IIXǹv Пapμevidov. Parmenides, the greatest name to the Eleatic School and here made its representative (though Xenophanes before him, and Zeno after him, taught similar principles), held the doctrine directly opposed to the Heracleitean, namely, that the universe is one, continuous, stable: that only 'being' is; 'non-being' is not; there is no 'becoming.'

6 'ЕμπedокλŶs. Prof. Campbell justly says that Plato introduced the words κράσεως πρὸς ἄλληλα in order to include Empedocles of Agrigentum, who, without accepting the doctrine of Heracleitus, that οὐδὲν ἔστι, πάντα γίγνεται, denied the Eleatic unity, continuity and stability of substance, teaching that phenomenal changes are caused by the intermixture of four elements (fire, air, water, earth) which are themselves alone unchangeable.

in the comic, Epicharmus', in the tragic, Homer; for in saying

Ocean of gods progenitor and Tethys mother

he has said that all things are born from flux and motion. Does he not seem to say so?

Theae. I think he does.

[The Heracleitean doctrine (τávтa þeî) is further expounded and seemingly 9 defended. But, as it is confuted afterwards (28), we must explain this defence as an instance of the Socratic elpwveía.]

So. After this then, who that disputes with so great a host, and Homer its captain, can avoid making himself ridiculous?

Theae. It were not easy, Socrates.
So.

No indeed, Theaetetus.

Since our statementthat motion produces the semblant' 'being,' and the 'coming to be,' while 'non-being' and 'perishing' are produced by rest—has in its favour many competent proofs. The heat of fire, which engenders and protects other things, is itself engendered by vection and attrition. And these are

motions. Are not these the parents of fire?

7'Erlxapuos. Diogenes Laertius, III. 10, quotes verses from Epicharmus, the comic poet of Syracuse (490 B. C.), which contain the doctrine of perpetual mutation.

8 Tpaywdías dè"Ounpos. Plato recognizes only two forms of poetry, viz. Comedy and Tragedy, including in the latter Epic poetry, and its great master Homer. See Rep. X. 495 D, étɩokETTÉOV TÝV TE TPAɣwdlav καὶ τὸν ἡγέμονα αὐτῆς ̔́Ομηρον.

9 1 Tò μèv elvai doкoûν. As he is professing to expound the Heracleitean theory, which does not admit rò eival, he evasively says To elvai dokoûv, 'the semblant being.'

2 Toúтw dè kɩvýoes. This is the reading in most codd., for which

Theae. They are.

So. Moreover the race of animals is produced from them?

Theae. To be sure.

So. Again is not the habit of bodies ruined by rest and laziness, and preserved in general3 by exercise and motion?

Theae. Yes.

So. And does not the habit of the soul by learning and study, which are motions, acquire doctrines and preserve them and become better, while through rest, which is the absence of study and learning, it both learns nothing, and forgets what it has learnt?

Theae. Decidedly.

So. The one then, namely motion, is a good both in soul and body, the other is the reverse.

Theae. Seemingly.

So. Must I farther mention to you calms and serenities and such-like things, showing that quietudes rot and destroy, while their opposites preserve? and besides these must I clinch the matter, and evince that by the golden cord Homer means nothing but the sun, and indicates that, as long as the revolution continues, and the sun keeps moving,

6

κινήσει (dual) is suggested. But some have τοῦτο δὲ κίνησις, which Bekker edits, and Campbell approves.

3 In general, ús éπì tò πoλù, read in many codd. and by Stobaeus. Professors Jowett and Campbell prefer èπì πоλù 'for a long time,' as in cod. Bodl.

4 Σώζεται. The middle voice of σώζω is specially used of memory. 5 Τὸν κολοφῶνα ἀναγκάζω προσβίβαζων ; ' must I bring up my crowning reason and prove conclusively (åvaykášw)'? See Strabo's explanation of koλopwv in Liddell and Scott's Lexicon. Others have been given, for which see Heindorf's note.

6 For Homer's Xpvon σeipά see Il. VIII. 47.

all things in heaven and earth exist and are preserved; but should this stand still as if fettered, all things would be spoilt, and, as the saying is, turned upside down?

Theae. In my judgment, Socrates, he does indicate what you say.

[The relativity of the facts of sensation is illustrated by the phenomena of 10 colour, number and size. What you call colour has no definite place

or existence within or without you. It is the result of a passing collision between your eyes and the flux of things suited to act on them. It is neither in the agent nor in the patient, but generated in passage between them. It will not be the same to two subjects nor to the same subject at different times. The object measured or touched cannot be in itself great, white, hot or anything else; if it were, it would not appear different to another subject. The subject touching or measuring cannot be any of these, for, if so, it would be so always, and would not be modified by application to another object. Socrates illustrates by six dice, which, as compared with four, are more, and half as many again (i.e. 3 2), but fewer and half compared with twelve (i.e. 1:2). Can then anything become more without being increased; or fewer without being diminished? Theaetetus is puzzled; and Socrates merrily suggests that they are amusing themselves with mere quibbles, like Megarian disputants.]

So. Conceive the matter in this way, my good friend. As to vision first: that what you call white colour is not in itself something outside your eyes or in your eyes. And do not assign to it any place for then, being somewhere in position, it would 'be' and remain, and would not by generation 'come to be.'

Theae. How so?

:

So. Let us follow the doctrine we were lately stating, that nothing exists as an independent unit; and in that way we shall see that black and white and every other colour have come to be' from the coincidence of the eyes with the suitable motion; and that what in each case we call

colour, is neither that which makes nor that which receives the impact, but something between, which is peculiar to each. Or would you insist that what each colour appears to you, such it appears also to a dog or any other animal?

Theae. No indeed, I would not.

So. Again: does anything appear to another man like what it appears to you? Are you strongly convinced it does, or are you much rather sure that even to yourself it is not the same, because at no two times are you exactly the same?

Theae. The latter seems to me truer than the former.

So. Accordingly, if a thing beside which we measure ourselves, or which we handle, were large or white or hot, it would never have become different by contact with some other, unless it underwent a change in itself. And if again the measuring or handling subject had been any of these, it would not have become different when another approached or suffered any affection, if there were no affection in itself. For now, my friend, we are compelled in a careless sort of way to say marvellous and ridiculous things, as Protagoras would affirm, and every one who ventures to propound the same that he does.

mean.

Theae. How do you mean? and what kind of things? So. Take a small sample, and you will know what I Six dice, if you place four beside them, we say are more in number and half as many again. If you bring twelve, we say the six are fewer in number, and half the second set. To say otherwise were intolerable. Will you tolerate it?

Theae. No, I will not.

So. Well: suppose Protagoras or some one else were to ask you:-Theaetetus, is it possible for anything to