Str. Now we have not discussed all those who treat accurately of being and not-being The Ionic philosophers, the Eleatics, Heracleitus, Empedocles, the Megarians, Gorgias, Protagoras, and Antisthenes all discussed the problem of being and not-being. ; however, let this suffice. But we must turn our eyes to those whose doctrines are less precise, that we may know from all sources that it is no easier
 to define the nature of being than that of not-being. Theaet. Very well, then, we must proceed towards those others also. Str. And indeed there seems to be a battle like that of the gods and the giants going on among them, because of their disagreement about existence. Theaet. How so? Str. Some of them The atomists (Leucippus, Democritus, and their followers), who taught that nothing exists except atoms and the void. Possibly there is a covert reference to Aristippus who was, like Plato, a pupil of Socrates. drag down everything from heaven and the invisible to earth, actually grasping rocks and trees with their hands; for they lay their hands on all such things and maintain stoutly that that alone exists which can be touched and handled; 
 for they define existence and body, or matter, as identical, and if anyone says that anything else, which has no body, exists, they despise him utterly, and will not listen to any other theory than their own. Theaet. Terrible men they are of whom you speak. I myself have met with many of them. Str. Therefore those who contend against them defend themselves very cautiously with weapons derived from the invisible world above, maintaining forcibly that real existence consists of certain ideas which are only conceived by the mind and have no body. But the bodies of their opponents, and that which is called by them truth, they break up into small fragments
 in their arguments, calling them, not existence, but a kind of generation combined with motion. There is always, Theaetetus, a tremendous battle being fought about these questions between the two parties. Theaet. True. Str. Let us, therefore, get from each party in turn a statement in defence of that which they regard as being. Theaet. How shall we get it? Str. It is comparatively easy to get it from those who say that it consists in ideas, for they are peaceful folk; but from those who violently drag down everything
 into matter, it is more difficult, perhaps even almost impossible, to get it. However, this is the way I think we must deal with them. Theaet. What way? Str. Our first duty would be to make them really better, if it were in any way possible; but if this cannot be done, let us pretend that they are better, by assuming that they would be willing to answer more in accordance with the rules of dialectic than they actually are. For the acknowledgement of anything by better men is more valid than if made by worse men. But it is not these men that we care about; we merely seek the truth. Theaet. Quite right. Str. Now tell them, assuming that they have become better, to answer you, and do you interpret what they say. Theaet. I will do so. Str. Let them tell whether they say there is such a thing as a mortal animal. Theaet. Of course they do. Str. And they agree that this is a body with a soul in it, do they not? Theaet. Certainly. Str. Giving to soul a place among things which exist? Theaet. Yes. Str. Well then, do they not say that one soul is just and another unjust, one wise and another foolish? Theaet. Of course. Str. And do they not say that each soul becomes just by the possession and presence of justice, and the opposite by the possession and presence of the opposite? Theaet. Yes, they agree to this also. Str. But surely they will say that that which is capable of becoming present or absent exists. Theaet. Yes, they say that. Str. Granting, then, that justice and wisdom and virtue in general and their opposites exist, and also, of course, the soul in which they become present, do they say that any of these is visible and tangible, or that they are all invisible? Theaet. That none of them is visible, or pretty nearly that. Str. Now here are some other questions. Do they say they possess any body? Theaet. They no longer answer the whole of that question in the same way. They say they believe the soul itself has a sort of body, but as to wisdom and the other several qualities about which you ask, they have not the face either
 to confess that they have no existence or to assert that they are all bodies. Str. It is clear, Theaetetus, that our men have grown better; for the aboriginal sons of the dragon’s teeth This refers to the story of Cadmus, who killed a dragon and then sowed its teeth, from which sprang fierce warriors to be his companions. Born of the dragon’s teeth and of earth, they would naturally be of the earth, earthy. among them would not shrink from any such utterance; they would maintain that nothing which they cannot squeeze with their hands has any existence at all. Theaet. That is pretty nearly what they believe. Str. Then let us question them further; for if they are willing to admit that any existence, no matter how small, is incorporeal,
 that is enough. They will then have to tell what is which is inherent in the incorporeal and the corporeal alike, and which they have in mind when they say that both exit. Perhaps they would be at a loss for an answer; and if they are in that condition, consider whether they might not accept a suggestion if we offered it, and might not agree that the nature of being is as follows. Theaet. What is it? Speak, and we shall soon know. Str. I suggest that everything which possesses any power of any kind, either to produce a change in anything of any nature
 or to be affected even in the least degree by the slightest cause, though it be only on one occasion, has real existence. For I set up as a definition which defines being, that it is nothing else but power. Theaet. Well, since they have at the moment nothing better of their own to offer, they accept this. Str. Good; for perhaps later something else may occur to them and to us. As between them
 and us, then, let us asume that this is for the present agreed upon and settled. Theaet. It is settled. Str. Then let us go to the others, the friends of ideas; and do you interpret for us their doctrines also. Theaet. I will. Str. You distinguish in your speech between generation and being, do you not? i.e., between the process of coming into existence and existence itself. It is difficult to determine exactly who the idealists are whose doctrines are here discussed. Possibly Plato is restating or amending some of his own earlier beliefs. Theaet. Yes, we do. Str. And you say that with the body, by means of perception, we participate in generation, and with the soul, by means of thought, we participate in real being, which last is always unchanged and the same, whereas generation is different at different times. Theaet. Yes, that is what we say. Str. But, most excellent men, how shall we define this participation which you attribute to both? Is it not that of which we were just speaking? Theaet. What is that? Str. A passive or active condition arising out of some power which is derived from a combination of elements. Possibly, Theaetetus, you do not hear their reply to this, but I hear it, perhaps, because I am used to them. Theaet. What is it, then, that they say? Str. They do not concede to us what we said just now to the aboriginal giants about being. Theaet. What was it? Str. We set up as a satisfactory sort of definition of being, the presence of the power to act or be acted upon in even the slightest degree. Theaet. Yes. Str. It is in reply to this that they say generation participates in the power of acting and of being acted upon, but that neither power is connected with being. Theaet. And is there not something in that? Str. Yes, something to which we must reply that we still need to learn more clearly from them whether they agree that the soul knows and that being is known. Theaet. They certainly assent to that. Str. Well then, do you say that knowing or being known is an active or passive condition, or both? Or that one is passive and the other active? Or that neither has any share at all in either of the two? Theaet. Clearly they would say that neither has any share in either; for otherwise they would be contradicting themselves. Str. I understand; this at least is true,
 that if to know is active, to be known must in turn be passive. Now being, since it is, according to this theory, known by the intelligence, in so far as it is known, is moved, since it is acted upon, which we say cannot be the case with that which is in a state of rest. Theaet. Right. Str. But for heaven’s sake, shall we let ourselves easily be persuaded that motion and life and soul and mind are really not present to absolute being, that it neither lives nor thinks,
 but awful and holy, devoid of mind, is fixed and immovable? Theaet. That would be a shocking admission to make, Stranger. Str. But shall we say that it has mind, but not life? Theaet. How can we? Str. But do we say that both of these exist in it, and yet go on to say that it does not possess them in a soul? Theaet. But how else can it possess them? Str. Then shall we say that it has mind and life and soul, but, although endowed with soul, is absolutely immovable? Theaet. All those things seem to me absurd. Str. And it must be conceded that motion and that which is moved exist. Theaet. Of course. Str. Then the result is, Theaetetus, that if there is no motion, there is no mind in anyone about anything anywhere. Theaet. Exactly. Str. And on the other hand, if we admit that all things are in flux and motion, we shall remove mind itself from the number of existing things by this theory also. Theaet. How so? Str. Do you think that sameness of quality or nature
 or relations could ever come into existence without the state of rest? Theaet. Not at all. Str. What then? Without these can you see how mind could exist or come into existence anywhere? Theaet. By no means. Str. And yet we certainly must contend by every argument against him who does away with knowledge or reason or mind and then makes any dogmatic assertion about anything. Theaet. Certainly. Str. Then the philosopher, who pays the highest honor to these things, must necessarily, as it seems, because of them refuse to accept the theory of those who say the universe is at rest, whether as a unity or in many forms,
 and must also refuse utterly to listen to those who say that being is universal motion; he must quote the children’s prayer, Nothing further seems to he known about this prayer. Stallbaum thought the reference was to a game in which the children said ὅσα ἀκίνητα καὶ κεκινημένα εἴη , may all unmoved things be moved. all things immovable and in motion, and must say that being and the universe consist of both. Theaet. Very true. Str. Do we not, then, seem to have attained at last a pretty good definition of being? Theaet. Certainly. Str. But dear me, Theaetetus! I think we are now going to discover the difficulty of the inquiry about being. Theaet. What is this again? What do you mean? Str. My dear fellow, don’t you see that we are now densely ignorant about it, but think that we are saying something worth while? Theaet. I think so, at any rate, and I do not at all understand what hidden error we have fallen into. Str. Then watch more closely and see whether, if we make these admissions,
 we may not justly be asked the same questions we asked a while ago of those who said the universe was hot and cold. Cf. 242d above. Theaet. What questions? Remind me. Str. Certainly; and I will try to do this by questioning you, as we questioned them at the time. I hope we shall at the same time make a little progress. Theaet. That is right. Str. Very well, then; you say that motion and rest are most directly opposed to each other, do you not? Theaet. Of course. Str. And yet you say that both and each of them equally exist? Theaet. Yes, I do. Str. And in granting that they exist, do you mean to say that both and each are in motion? Theaet. By no means. Str. But do you mean that they are at rest, when you say that both exist? Theaet. Of course not. Str. Being, then, you consider to be something else in the soul, a third in addition to these two, inasmuch as you think rest and motion are embraced by it; and since you comprehend and observe that they participate in existence, you therefore said that they are. Eh? Theaet. We really do seem to have a vague vision of being as some third thing, when we say that motion and rest are. Str. Then being is not motion and rest in combination, but something else, different from them. Theaet. Apparently. Str. According to its own nature, then, being is neither at rest nor in motion. Theaet. You are about right. Str. What is there left, then, to which a man can still turn his mind who wishes to establish within himself any clear conception of being? Theaet. What indeed? Str. There is nothing left, I think, to which he can turn easily. For if
 a thing is not in motion, it must surely be at rest; and again, what is not at rest, must surely be in motion. But now we find that being has emerged outside of both these classes. Is that possible, then? Theaet. No, nothing could be more impossible. Str. Then there is this further thing which we ought to remember. Theaet. What is it? Str. That when we were asked to what the appellation of not-being should be applied, we were in the greatest perplexity. Do you remember? Theaet. Of course I do. Str. Well, then, are we now in any less perplexity
 about being? Theaet. It seems to me, stranger, that we are, if possible, in even greater.