Dialogues

appear either as one or many.

Why not?

Because the others have no sort or manner or way of communion with any sort of not-being, nor can anything which is not, be connected with any of the others; for that which is not has no parts.

True.

Nor is there an opinion or any appearance of not-being in connection with the others, nor is not-being ever in any way attributed to the others.

No.

Then if one is not, there is no conception of any of the others either as one or many; for you cannot conceive the many without the one.

You cannot.

Then if one is not, the others neither are, nor can be conceived to be either one or many?

It would seem not.

Nor as like or unlike?

No.

Nor as the same or different, nor in contact or separation, nor in any of those states which we enumerated as appearing to be;⁠—the others neither are nor appear to be any of these, if one is not?

True.

Then may we not sum up the argument in a word and say truly: If one is not, then nothing is?

Certainly.

Let thus much be said; and further let us affirm what seems to be the truth, that, whether one is or is not, one and the others in relation to themselves and one another, all of them, in every way, are and are not, and appear to be and appear not to be.

Most true.

Theaetetus

Introduction and Analysis

Some dialogues of Plato are of so various a character that their relation to the other dialogues cannot be determined with any degree of certainty. The “Theaetetus,” like the “Parmenides,” has points of similarity both with his earlier and his later writings. The perfection of style, the humour, the dramatic interest, the complexity of structure, the fertility of illustration, the shifting of the points of view, are characteristic of his best period of authorship. The vain search, the negative conclusion, the figure of the midwives, the constant profession of ignorance on the part of Socrates, also bear the stamp of the early dialogues, in which the original Socrates is not yet Platonized. Had we no other indications, we should be disposed to range the “Theaetetus” with the “Apology” and the “Phaedrus,” and perhaps even with the “Protagoras” and the “Laches.”

But when we pass from the style to an examination of the subject, we trace a connection with the later rather than with the earlier dialogues. In the first place there is the connection, indicated by Plato himself at the end of the dialogue, with the “Sophist,” to which in many respects the “Theaetetus” is so little akin. (1) The same persons reappear, including the younger Socrates, whose name is just mentioned in the “Theaetetus” (147 C); (2) the theory of rest, which at 183 D Socrates has declined to consider, is resumed by the Eleatic Stranger; (3) there is a similar allusion in both dialogues to the meeting of Parmenides and Socrates (“Theaetetus” 183 E, “Sophist” 217); and (4) the inquiry into not-being in the “Sophist” supplements the question of false opinion which is raised in the “Theaetetus.” (Compare also “Theaetetus” 168 A, 210, and “Sophist” 230 B; “Theaetetus” 174 D, E, and “Sophist” 227 A; “Theaetetus” 188 E, and “Sophist” 237 D; “Theaetetus” 179 A, and “Sophist” 233 B; “Theaetetus” 172 D, “Sophist” 253 C, for parallel turns of thought.) Secondly, the later date of the dialogue is confirmed by the absence of the doctrine of recollection and of any doctrine of ideas except that which derives them from generalization and from reflection of the mind upon itself. The general character of the “Theaetetus” is dialectical, and there are traces of the same Megarian influences which appear in the “Parmenides,” and which later writers, in their matter of fact way, have explained by the residence of Plato at Megara. Socrates disclaims the character of a professional eristic (164 C), and also, with a sort of ironical admiration, expresses his inability to attain the Megarian precision in the use of terms (197 A). Yet he too employs a similar sophistical skill in overturning every conceivable theory of knowledge.

The direct indications of a date amount to no more than this: the conversation is said to have taken place when Theaetetus was a youth, and shortly before the death of Socrates. At the time of his own death he is supposed to be a full-grown man. Allowing nine or ten years for the interval between youth and manhood, the dialogue could not have been written earlier than 390, when Plato was about thirty-nine years of age. No more definite date is indicated by the engagement in which Theaetetus is said to have fallen or to have been wounded, and which may have taken place any time during the Corinthian war, between the years 390⁠–⁠387. The later date which has been suggested, 369, when the Athenians and Lacedaemonians disputed the Isthmus with Epaminondas, would make the age of Theaetetus at his death forty-five or forty-six. This a little impairs the beauty of Socrates’ remark, that “he would be a great man if he lived.”

In this uncertainty about the place of the “Theaetetus,” it seemed better, as in the case of the Republic, “Timaeus,” “Critias,” to retain the order in which Plato himself has arranged this and the two companion dialogues. We cannot exclude the possibility which has been already noticed in reference to other works of Plato, that the “Theaetetus” may not have been all written continuously; or the probability that the “Sophist” and “Politicus,” which differ greatly in style, were only appended after a long interval of time. The allusion to “Parmenides” at 183 compared with “Sophist” 217, would probably imply that the dialogue which is called by his name was already in existence; unless, indeed, we suppose the passage in which the allusion occurs to have been inserted afterwards. Again,