Soc. I see, my dear Theaetetus, that Theodorus had a true insight into your nature when he said that you were a philosopher, for wonder is the feeling of a philosopher, and philosophy begins in wonder. He was not a bad genealogist who said that Iris (the messenger of heaven) is the child of Thaumas (wonder). But do you begin to see what is the explanation of this perplexity on the hypothesis which we attribute to Protagoras ?
Theaet. Not as yet.
Soc. Then you will be obliged to me if I help you to unearth the hidden “truth” of a famous man or school.
Theaet. To be sure, I shall be very much obliged.
Soc. Take a look round, then, and see that none of the uninitiated are listening. Now by the uninitiated I mean : the people who believe in nothing but what they can grasp in their hands, and who will not allow that action or generation or anything invisible can have real existence.
Theaet. Yes, indeed, Socrates, they are very hard and impenetrable mortals.
Soc. Yes, my boy, outer barbarians. Far more ingenious are the brethren whose mysteries I am about to reveal to you. Their first principle is, that all is motion, and upon this all the affections of which we were just now speaking, are supposed to depend : there is nothing but motion, which has two forms, one active and the other passive, both in endless number ; and out of the union and friction of them there is generated a progeny endless in number, having two forms, sense and the object of sense, which are ever breaking forth and coming to the birth at the same moment. The senses are variously named hearing, seeing, smelling ; there is the sense of heat, cold, pleasure, pain, desire, fear, and many more which have names, as well as innumerable others which are without them ; each has its kindred object each variety of colour has a corresponding variety of sight, and so with sound and hearing, and with the rest of the senses and the objects akin to them. Do you see, Theaetetus, the bearings of this tale on the preceding argument ?
Theaet. Indeed I do not.
Soc. Then attend, and I will try to finish the story. The purport is that all these things are in motion, as I was saying, and that this motion is of two kinds, a slower and a quicker ; and the slower elements have their motions in the same place and with reference to things near them, and so they beget ; but what is begotten is swifter, for it is carried to fro, and moves from place to place. Apply this to sense : — When the eye and the appropriate object meet together and give birth to whiteness and the sensation connatural with it, which could not have been given by either of them going elsewhere, then, while the sight : is flowing from the eye, whiteness proceeds from the object which combines in producing the colour ; and so the eye is fulfilled with sight, and really sees, and becomes, not sight, but a seeing eye ; and the object which combined to form the colour is fulfilled with whiteness, and becomes not whiteness but a white thing, whether wood or stone or whatever the object may be which happens to be colour,ed white. And this is true of all sensible objects, hard, warm, and the like, which are similarly to be regarded, as I was saying before, not as having any absolute existence, but as being all of them of whatever kind. generated by motion in their intercourse with one another ; for of the agent and patient, as existing in separation, no trustworthy conception, as they say, can be formed, for the agent has no existence until united ; with the patient, and the patient has no existence until united with the agent ; and that which by uniting with something becomes an agent, by meeting with some other thing is converted into a patient. And from all these considerations, as I said at first, there arises a general reflection, that there is no one self-existent thing, but everything is becoming and in relation ; and being must be altogether abolished, although from habit and ignorance we are compelled even in this discussion to retain the use of the term. But great philosophers tell us that we are not to allow either the word “something,” or “belonging to something,” or “to me,” or “this,” or “that,” or any other detaining name to be used, in the language of nature all things are being created and destroyed, coming into being and passing into new forms ; nor can any name fix or detain them ; he who attempts to fix them is easily refuted. And this should be the way of speaking, not only of particulars but of aggregates such aggregates as are expressed in the word “man,” or “stone,” or any name of animal or of a class. O Theaetetus, are not these speculations sweet as honey ? And do you not like the taste of them in the mouth ?
Theaet. I do not know what to say, Socrates, for, indeed, I cannot make out whether you are giving your own opinion or only wanting to draw me out.
Soc. You forget, my friend, that I neither know, nor profess to know, anything of ! these matters ; you are the person who is in labour, I am the barren midwife ; and this is why I soothe you, and offer you one good thing after another, that you may taste them. And I hope that I may at last help to bring your own opinion into the light of day : when this has been accomplished, then we will determine whether what you have brought forth is only a wind-egg or a real and genuine birth. Therefore, keep up your spirits, and answer like a man what you think.
Theaet. Ask me.
Soc. Then once more : Is it your opinion that nothing is but what becomes ? the good and the noble, as well ; as all the other things which we were just now mentioning ?
Theaet. When I hear you discoursing in this style, I think that there is a great deal in what you say, and I am very ready to assent. Soc. Let us not leave the argument unfinished, then ; for there still remains to be considered an objection which may be raised about dreams and diseases, in particular about madness, and the various illusions of hearing and sight, or of other senses. For you know that in all these cases the esse-percipi theory appears to be unmistakably refuted, since in dreams and illusions we certainly have false perceptions ; and far from saying that everything is which appears, we should rather say that nothing is which appears.
Theaet. Very true, Socrates.
Soc. But then, my boy, how can any one contend that knowledge is perception, or that to every man what appears is ?
Theaet. I am afraid to say, Socrates, that I have nothing to answer, because you rebuked me just now for making this excuse ; but I certainly cannot undertake to argue that madmen or dreamers think truly, when they imagine, some of them that they are gods, and others that they can fly, and are flying in their sleep.
Soc. Do you see another question which can be raised about these phenomena, notably about dreaming and waking ?
Theaet. What question ?
Soc. A question which I think that you must often have heard persons ask : — How can you determine whether at this moment we are sleeping, and all our thoughts are a dream ; or whether we are awake, and talking to one another in the waking state ?
Theaet. Indeed, Socrates, I do not know how to prove the one any more than the other, for in both cases the facts precisely correspond ; — and there is no difficulty in supposing that during all this discussion we have been talking to one another in a dream ; and when in a dream we seem to be narrating dreams, the resemblance of the two states is quite astonishing.
Soc. You see, then, that a doubt about the reality of sense is easily raised, since there may even be a doubt whether we are awake or in a dream. And as our time is equally divided between sleeping and waking, in either sphere of existence the soul contends that the thoughts which are present to our minds at the time are true ; and during one half of our lives we affirm the truth of the one, and, during the other half, of the other ; and are equally confident of both.
Theaet. Most true.
Soc. And may not the same be said of madness and other disorders ? the difference is only that the times are not equal.
Theaet. Certainly.
Soc. And is truth or falsehood to be determined by duration of time ?
Theaet. That would be in many ways ridiculous.
Soc. But can you certainly determine : by any other means which of these opinions is true ?
Theaet. I do not think that I can.
Soc. Listen, then to a statement of the other side of the argument, which is made by the champions of appearance. They would say, as I imagine — can that which is wholly other than something, have the same quality as that from which it differs ? and observe, — Theaetetus, that the word “other” means not “partially,” but “wholly other.”
Theaet. Certainly, putting the question as you do, that which is wholly other cannot either potentially or in any other way be the same.
Soc. And must therefore be admitted to be unlike ?
Theaet. True.
Soc. If, then, anything happens to become like or unlike itself or another, when it becomes like we call it the same — when unlike, other ?
Theaet. Certainly.
Soc. Were we not saying that there. are agents many and infinite, and patients many and infinite ?
Theaet. Yes.
Soc. And also that different combinations will produce results which are not the same, but different ?
Theaet. Certainly.
Soc. Let us take you and me, or anything as an example : — There is Socrates in health, and Socrates sick — Are they like or unlike ?
Theaet. You mean to, compare Socrates in health as a whole, and Socrates in sickness as a whole ?
Soc. Exactly ; that is my meaning.
Theaet. I answer, they are unlike.
Soc. And if unlike, they are other ?
Theaet. Certainly.
Soc. And would you not say the same of Socrates sleeping and waking, or in any of the states which we were mentioning ?
Theaet. I should.
Soc. All agents have a different patient in Socrates, accordingly as he is well or ill.
Theaet. Of course.
Soc. And I who am the patient, and that which is the agent, will produce something different in each of the two cases ?
Theaet. Certainly.
Soc. The wine which I drink when I am in health, appears sweet and pleasant to me ?
Theaet. True.
Soc. For, as has been already acknowledged, the patient and agent meet together and produce sweetness and a perception of sweetness, which are in simultaneous motion, and the perception which comes from the patient makes the tongue percipient, and the quality of sweetness which arises out of and is moving about the wine, makes the wine, both to be and to appear sweet to the healthy tongue.
Theaet. Certainly ; that has been already acknowledged.
Soc. But when I am sick, the wine really acts upon another and a different person ?
Theaet. Yes.
Soc. The combination of the draught of wine, and the Socrates who is sick, produces quite another result ; which is the sensation of bitterness in the tongue, and the, motion and creation of bitterness in and about the wine, which becomes not bitterness but something bitter ; as I myself become not but percipient ?
Theaet. True.
Soc. There is no, other object of which I shall ever have the same perception, for another object would give another perception, and would make the perception other and different ; nor can that object which affects me, meeting another, subject, produce, the same, or become similar, for that too would produce another result from another subject, and become different.
Theaet. True.
Soc. Neither can by myself, have this sensation, nor the object by itself, this quality.
Theaet. Certainly not.
Soc. When I perceive I must become percipient of something — there can be no such thing as perceiving and perceiving nothing ; the object, whether it become sweet, bitter, or of any other quality, must have relation to a percipient ; nothing can become sweet which is sweet to no one.
Theaet. Certainly not.
Soc. Then the inference is, that we [the agent and patient] are or become in relation to one another ; there is a law which binds us one to the other, but not to any other existence, nor each of us to himself ; and therefore we can only be bound to one another ; so that whether a person says that a thing is or becomes, he must say that it is or becomes to or of or in relation to something else ; but he must not say or allow any one else to say that anything is or becomes absolutely : — such is our conclusion.
Theaet. Very true, Socrates.
Soc. Then, if that which acts upon me has relation to me and to no other, I and no other am the percipient of it ?
Theaet. Of course.
Soc. Then my perception is true to me, being inseparable from my own being ; and, as Protagoras says, to myself I am judge of what is and what is not to me.
Theaet. I suppose so.
Soc. How then, if I never err, and if my mind never trips in the conception of being or becoming, can I fail of knowing that which I perceive ?
Theaet. You cannot.
Soc. Then you were quite right in affirming that knowledge is only perception ; and the meaning turns out to be the same, whether with Homer and Heracleitus, and all that company, you say that all is motion and flux, or with the great sage Protagoras, that man is the measure of all things ; or with Theaetetus, that, given these premises, perception is knowledge. Am I not right, Theaetetus, and is not this your newborn child, of which I have delivered you ? What say you ?
Theaet. I cannot but agree, Socrates.