Читать книгу PLATO - Hoshang Khambatta - Страница 17

Overview: The dialogue can be dated as it mentions the return of the mortally sick and wounded Theaetetus from Corinth after the Peloponnesian War, on his way to Athens. This dialogue is being read by a slave from a book written by Euclides. The book is a transcription of the conversation many years ago between Theaetetus, Theodorus the geometer, and Socrates. It is a primary dialogue on epistemology, which is the study of what knowledge is. Epistemology was a main preoccupation of the ancient philosophers and this, perhaps, is the greatest work ever composed on the subject. Most of this book is in the form of a question and answer dialogue between Socrates and Theaetetus. They wish to understand the nature of knowledge. Socrates likens himself to the midwife who helps women deliver their babies. In this dialogue he will again act as a midwife and help Theaetetus deliver his thoughts on what is knowledge. First they look at various crafts as knowledge, but reject this approach as it describes knowledge “of ” rather than what knowledge “is.” They then put forward three significant hypotheses. First, perception is knowledge. Perception is obtained from the senses, but maybe perceived differently by different people. Thus, perception cannot be knowledge. Another possibility is that true judgment is knowledge. This definition, too, is rejected because, as with perception, judgments may be due to sensory awareness. Sensations are the source of all belief, but as true or false beliefs cannot be determined, true judgment is difficult to define. Thus true judgment cannot be knowledge. Finally knowledge is defined as true judgment with an account. This proposition is also known as Socrates’ Dream Theory, as he narrates it as a dream that he has had. This definition is also rejected as there cannot be an account for false belief. All three suggestions are discussed in detail, but eventually all are rejected. In the end, in frustration, Socrates concludes that all they have produced is “wind – eggs.” It was an aporetic discussion. Meaning that it ended in an inconclusive impasse, as all the suggestions offered were ultimately inadequate. Plato does not provide an answer to what knowledge is, though he does show what it is not.

Euclides and Terpsion meet at the market place in Megra. Euclides reports that he was at the harbor where he met Theaetetus, who was being taken to Athens from his camp at Corinth during the Peloponnesian War. He was badly wounded on the battlefield but felt worse now, as he was also suffering from dysentery. Euclides related that he had heard people singing Theaetetus’ praises because of how valiantly he fought. Terpsion comments that he would have been more surprised had it been otherwise. Euclides says that he tried to persuade Theaetetus to stay in Megra until he had recovered from his illness, but Theaetetus was in a hurry to get home to Athens. Euclides then reminisced about Socrates having met Theaetetus when Theaetetus was a young man. After a discussion with Theaetetus, Socrates predicted that Theaetetus would have much to say when he was grownup. Terpsion concurs that Socrates was correct in his assessment of the young Theaetetus and asks what Theaetetus had discussed with Socrates that was so impressive. Euclides says that he wrote down the whole discussion from memory in a book and then checked the details with Socrates whenever he was not sure of his own memory. This discussion was between Theodorus the geometer, Theaetetus and Socrates.

Euclides then has his slave read the book to them. In this book Socrates begins by asking Theodorus if he has come across any students worthy of note? Theodorus replies that he has indeed. He speaks of an extremely gifted young man called Theaetetus who has facial features very similar to Socrates’. While the two men are conversing, they see Theaetetus walking towards them. Socrates has Theodorus ask Theaetetus to join them in conversation.

Socrates tells Theaetetus that, because Theodorus told him that Theaetetus’ face looks like his own, he would like to see what sort of face Theaetetus has. They agree that it is necessary that they look into this claim. Socrates adds that Theodorus has never praised anyone as he has praised Theaetetus, so they must look into that as well. Socrates begins by asking Theaetetus if he was learning geometry from Theodorus. Theaetetus replies that this is indeed so and adds that he is also being tutored in astronomy and arithmetic.

Socrates then confesses that he has some difficulty grasping a few things. For example, he notes that it is said that to learn is to become wiser about the things one is learning and that what makes people wise is wisdom. Therefore, he asks whether wisdom is the same thing as knowledge. To this remark, Theaetetus replies in the affirmative. Socrates now counters that he has difficulty in understanding what knowledge is, and asks whether anyone can explain that to him in a few words. Theaetetus tries to explain that what Theodorus teaches is knowledge such as geometry and all the other subjects. He adds that there are crafts such as cobbling that are also knowledge. Socrates tells him that he had asked for a simple explanation but that all that he received was a variety of examples. Theaetetus responds that he is unable to follow Socrates’ logic. Socrates tries to explain by asking whether talk about cobbling means just the knowledge of shoe making. Theaetetus replies that that is all he means. Socrates asks whether talking about carpentry, means the knowledge of making furniture. Once again Theaetetus says yes. Socrates then states that in both these examples Theaetetus was putting into his definition that which the knowledge encompasses. Theaetetus agrees with this proposition. Then, Socrates tells him that he had asked for something different. He explains that he did not ask what a person can have knowledge of; but he wants to know what knowledge itself is. Theaetetus says that he understands, prompting Socrates to give another example. He points out that if he had asked what clay is, and Theaetetus had answered the clay of potters, and the clay of brick makers, and the clay of the stove makers, those responses would be absurd. Theaetetus hesitantly agrees with this conclusion by Socrates. Socrates then emphasizes his response, saying that the person would not understand anything when he does not know what that thing (in this case, clay) is. Therefore, listing all the users of clay does not help in understanding what clay is. Thus, it follows that a man who does not understand what knowledge is will not understand the knowledge of shoes either. Furthermore, a man who does not understand what knowledge is will not understand what cobbling, or indeed any other craft, is. Socrates further emphasizes that when the question at hand is what knowledge is, to reply by naming one of the crafts is absurd. Such an answer points out something about what the knowledge might encompass, but does not answer the question of what knowledge is. Socrates adds that the best way to answer a query about the nature of clay is to say that it is a mixture of earth with liquid and point out whose clay it is.

Socrates persuades Theaetetus to try to come up with an answer to the question of what knowledge is. Socrates likens himself to a midwife. As a midwife delivers babies, he is helping Theaetetus deliver answers. After much persuasion, Theaetetus comes up with an answer. A man who knows something perceives what he knows which defines knowledge simply as perception. Socrates is pleased with this reply as a frank answer, and therefore suggests that they must continue to discuss it. Socrates then points out that the sophist Protagoras also believed this definition by repeating Protagoras’ famous quote. “Man is the measure of all things, of the things which are, that they are, and the things which are not, that they are not.” This saying means that things that appear to me are true for me and things that appear to you are true for you. Theaetetus agrees with this explanation. Socrates adds that Protagoras, who is now dead, cannot defend himself, but having been a wise man, he was unlikely to have talked nonsense. Therefore, the statement requires further discussion. Socrates starts by giving an example of blowing wind. One person will feel cold but another will not. Thus, the same blowing wind appears to have a different effect to each individual. He explains that appears means as perceived by each of us and perception should be unerring, as befits knowledge. However, in this case each person has perceived the same thing differently. Socrates suggests that perhaps Protagoras put his statement out as a riddle for the common folk, but revealed the meaning in his book entitled Truth, in which he claimed that nothing in itself is just one thing. For example, calling a thing large overlooks the fact that it will be small in comparison to something larger. Likewise, something that might be judged heavy may be light in comparison to a yet heavier thing. Nothing is only one of anything or one of any kind of thing. Therefore, it comes down to this: When a person says that things “are,” they are consequently in a process of coming to be as a result of change. Socrates adds that this theory shows that being and becoming are products of motion, while not being and passing away originate from a state of rest. He goes on to say that heat is fire, and heat is generated by movement such as friction. Movement and motion generate everything. For example resting degenerates the body, whereas, in contrast, constant motion strengthens the body. This same difference applies with the condition of the soul. Learning and studying are motions; therefore the soul gains knowledge and thrives. In the state of rest, when the soul is not learning anything, a person not only fails to acquire knowledge but also forgets what he has previously learned. Thus, one can conclude that motion is beneficial for both body and soul. Socrates adds that what is perceived and its’ perception are similar. He concludes that perhaps the words “to be” ought to be abolished because there is continuous motion. This constant flux means that nothing can be said to be, but rather that everything is “coming to be.” Socrates once again wants to consider whether knowledge and perception are the same or different. He asks, whether a man who has learned something can be capable of not knowing it when recollecting it. Theaetetus says that this cannot happen. Socrates points out that seeing is perceiving and that sight is perception. Therefore a man who has seen something has come to know what he has seen. However, there is also something called “memory” to consider. So once something has been seen, it can be recalled at any time. It can be recalled even with the eyes shut. This situation, then, is different from what was discussed previously. A man who sees something has acquired knowledge of what he sees. Therefore, sight perception and knowledge are the same thing. Once a man has acquired knowledge of the object seen, he can remember it with his eyes shut. To say that he does not see it is to say that he does not know it, so if he sees, he knows. Socrates says that what all this means is that a man who has come to know and remember something, knows it even though he does not see it. This knowing is impossible when knowledge and perception are taken to be the same thing. Hence, it turns out that knowledge is one thing and perception is another.

Socrates now poses another riddle. Is it possible for a man to know something and not to know this thing which he knows? Theaetetus replies that such a contradiction is impossible. Socrates asks what justification is there for saying that: “seeing is knowing.” In this fashion, Socrates scores several debating points over Theaetetus, who equated perception with knowledge. Socrates argues that the mind makes use of a range of concepts that it could not have acquired by observation and that do not operate through the senses. Hence, there is a part of knowledge that has nothing to do with perception. Thus, knowledge is not perception.

Socrates notes again that Protagoras is dead and can not defend his statement that “man is the measure of all things.” Instead, he will try to defend the statement and offers a long monologue to this end. He adds that instead of him tormenting the young Theaetetus, perhaps Theodorus should join him in the question-and-answer debate. Theodorus agrees to this proposal and he and Socrates further discuss Protagoras’ statement. Socrates starts by stating that, according to Protagoras, things are for every man what they appear to be to himself. Theodorus agrees with this supposition. Socrates then points out that this insight means that all men express judgments of mankind. Socrates continues pointing out that all men agree that in some matters they are wiser than others, but that in other matters other men are wiser than they. This conclusion is more so in emergencies and in difficult situations when people look to other men as well as to The Gods for help. This activity takes place because the men who are called upon to solve the difficulty are superior in one thing that is knowledge of the situation. This conclusion, then, equates to the notion that men believe in the existence of both wisdom and ignorance amongst themselves. They believe that wisdom is true thinking, and that ignorance leads to false judgment. Theodorus also agrees with this conclusion. Socrates then asks what should be made of Protagoras’ argument. Can it be said that on every occasion all men correctly judge what is true? Or do they sometimes judge truly and sometimes not? If the latter is true, then human judgment is both true and false. Would anyone from Protagoras’ school be prepared to say that no one ever thinks that his neighbor is ignorant or judges falsely? Theodorus agrees that such a statement is unlikely. Socrates proposes that Theodorus come to a decision in his own mind and express his own judgment about it. Socrates continues, saying to Theodorus: “as per Protagoras, your judgment is true for you, but what about others who may disagree?” It is inevitable that people have to accept that Theodorus’ judgment is always true? What about all the others who think the opposite? Socrates continues, stating that in such a situation, Theodorus would want everyone to accept his judgment as true, even though thousands may disagree with it. Socrates adds that Protagoras admits to a contrary opinion when he says that all men judge what is. Thus, by admitting to a contrary opinion, Protagoras has admitted to the falsity of his own opinion. In the end, even Protagoras would have to admit that no man is the measure of anything. Therefore, this so called truth of Protagoras is not true for anyone, including Protagoras himself. The conclusion is then that some men are wiser than their fellows and that some other men are more ignorant. Socrates once again takes up Theaetetus’ explanation that perception is knowledge and asks him how a man sees colors or hears sounds. One could answer with that of course seeing is done with eyes and hearing is done with ears. Socrates asks whether a more precise wording would be by the use of words which would explain that people see through their eyes and similarly hear through the ears rather than with the eyes and ears. Theaetetus answers that “through” would be a more precise word here. Socrates concurs, pointing out that otherwise it would seem that people have a number of perceptions inside of themselves and that there is not one single form through which all of them converge, call it soul, or whatever. Socrates argues that knowledge is found not in the expression of things but in the process of reasoning about things. Therefore, knowledge and perception can not be the same. Socrates reminds Theaetetus that they did not start the discussion to find out the negative, what knowledge is not, but rather to determine what it is.

Socrates says it may be necessary to look for knowledge in what we have called activity of the soul. Theaetetus replies that such an insight might be theirs’ and others’ own judgment. To this explanation, Socrates says that if such were the case they would have to start the inquiry all over again. Theaetetus tries to clarify his statement that it is not possible to say judgment in general, as there is both true and false judgment, but knowledge is true judgment. Socrates says that he has some difficulty with the experience of judging that is false. Socrates claims that false judgment can occur. One man judges falsely, while another judges truly. One either knows something or does not know it. When a man judges, he does so about something that he knows or something that he does not know. When a man judges falsely is he thinking that what he knows is not these things but other things, or is he ignorant of both? A man can not think that things he knows are things he does not know. So how can false judgment be possible? If everything is either something we know or do not know, false judgment is impossible.

At this point Socrates suggests that they take up a different line of inquiry. Instead of knowing and not knowing, he proposes that perhaps they should move to being and not being. Theaetetus asks for further clarification of this distinction. Socrates says that when a man judges things that are not there, then he is judging falsely. As an example, a man sees something, yet sees nothing. Theaetetus questions the meaning of that statement. Socrates answers that a man who is seeing anything is seeing something that is. Theaetetus agrees. Socrates goes through similar examples of hearing, touching, etcetera and concludes that a man who is judging one thing is judging something that is, therefore, he is not judging nothing. However, a man who is judging nothing is not judging anything at all. Therefore, it is not possible to judge what is not, either about a thing that is or is just by itself. Hence, false judgment is something different from judging things that are not. Socrates adds that there is false judgment when, in place of one of the things that is, the person substitutes his thoughts with another thing that is, and then asserts that substitution by his own thoughts is correct. In this way that man is always judging something that is, but really he is judging one thing in place of the other. Hence, having missed the thing that was the object of his observation he can be seen to be one who judges falsely. Theaetetus verbalizes Socrates’ argument that when a man judges “ugly” instead of “beautiful” or the other way around, he is truly judging what is false. Socrates asks if he approves the suggestion that false judgment is “other judging” and asks if it is possible to have in one’s thoughts the other thing and not the thing itself. Theaetetus answers positively, so Socrates asks whether a man should be thinking of one or of both of these things? Theaetetus replies that it is essential to consider either both things together or each in turn. Socrates asks Theaetetus if he agrees that his idea of what thinking is, is the same as his own? Theaetetus requests some clarity here. Socrates says that he believes that when a soul thinks, it asks itself questions and then answers them. This question-and-answer affirms a desire, and that is called judgment. Thus, to judge is to make a statement that is addressed to oneself. When a man judge’s one thing to be another, he is telling himself that one thing is the other. Socrates asks Theaetetus if he has ever tried to persuade himself that one thing is another thing: something like “a cow must be a horse.” Theaetetus replies in the negative. No one judges ugly to be beautiful, when someone has both things in his mind as he judges. He cannot possibly say that one is the other. Socrates says that he realizes that false judgment occurs, not in relation to a perception or thought of one thing in relation to another, but in the connecting of perception and thought. Socrates suggests that false judgment is other than misapplication of thought to perception, but that, too, is a problem. At this stage of their discussion, there is either no such thing as false judgment or a man may not know what he knows. Socrates notes that this conclusion shows that those who do not know what knowledge is, should not make pronouncements about what knowing is.

Socrates offers further examples. How can people say: “we are acquainted with” or “we are not acquainted with,” “we know,” or “we do not know,” if they are still ignorant of what knowledge is? When people say that they know something, it means that they have the knowledge of it. Socrates says that he would like to change this declaration to: “possession of knowledge.” Theaetetus questions how these two statements are different? Socrates explains that to possess is not the same as to have. He adduces the example of a man who buys a coat but is not wearing it. In that case it can be said that he possesses the coat but does not have it with him at that time. The same concept applies to knowledge. To possess knowledge is one thing, but to have knowledge is another thing. It is impossible for anyone not to possess something that he has possession of. In the same manner he cannot not fail to know something that he knows. Nonetheless, he can still make a false judgment about that knowledge because he may not have the proper knowledge of it. Socrates concludes that it is therefore impossible for a person not to know what he knows, the same way that it is impossible not to possess what one possesses. Therefore, false judgment is merely a matter of interchange of pieces of knowledge. Socrates gives another example. Suppose a jury has been persuaded on some matter that only an eye witness could have known. Then the jury comes to a decision on hearsay evidence, forming a true judgment. Albeit that the jury has decided without knowledge even though they were persuaded to come to a correct decision and did their job well. However, if true judgment is the same as knowledge, then the jury could not claim to have done well. Even the best juryman cannot form a correct judgment without knowledge. So Socrates concludes that true judgment and knowledge must be different. Once again the discussants are left at an impasse.

Theaetetus says that he once heard someone say that knowledge is true judgment with an account, while judgment without an account is not knowledge. Socrates replies that the problem is how to distinguish between the knowable and the unknowable. He begins to describe a dream he had. In his dream he heard that the primary elements from which everything in the world is composed have no account. It is not possible to say anything else about these elements except their names but, when things are composed of primary elements they become complexes of names. Therefore the elements are unaccountable and unknowable, but they are perceived just the same. However, the complexes are both knowable and expressible and therefore can be objects of true judgment. Theaetetus agrees that this distinction was just what he had heard. Socrates now asks Theaetetus if he agrees with the statement that knowledge is true judgment with an account. To this question Theaetetus replies in the affirmative. Socrates responds that he is surprised that they have found an answer to what wise men have been seeking for years and adds that there is one point with which he does not agree. It is that the elements are unknowable but the complexes are knowable. He continues, pointing out that when these statements were made, they were used as models, letters, elements language and syllables i.e., complexes. Socrates and Theaetetus then decide to examine this point. First, Socrates confirms that they have agreed that they can give an account of the syllables but not the letters, Theaetetus concurs. Next, Socrates asks what the first syllable of his name is. Theaetetus replies SO. Socrates asks what SO is? Theaetetus replies S and O. So that is an account of a syllable. Socrates then asks for an account of the letter S. Theaetetus replies that such an account is not possible, as it is merely a letter and hence unaccountable. Socrates says that they have proved the point that a syllable is knowable but not a letter. Now Socrates asks what people mean when they speak of a syllable. If a person knows the first two letters of his name then he must know both of the letters. The person can not be ignorant of each letter and yet know the two of them without knowing either. This restriction then proves that their initial theory was wrong. Socrates suggests an alternative condition. He proposes that a complex be considered as a single form resulting from a combination of several elements or things. Thus a complex cannot have parts, otherwise the whole thing will be different from the sum of its parts. Socrates comes up with another example, this time the number six. Five plus one, two plus four, two times three, they all equal six. Then he asks whether speaking of six means speaking of it as a sum of all these numbers. In that case there is no difference between a sum and part of a whole number. This means that the result of their initial discussion concerning letters and syllables was wrong. The two of them conclude that anyone who says that something that is a complex and that can be known and expressed, but has unknown elements is therefore wrong. Socrates now wants to go back to the original question as to what the addition of an account to true judgment means? He suggests that there are three possibilities for what is meant by account. The first would be expressing someone’s thoughts. Here, a man expresses the image of his judgment. Theaetetus agrees, but then Socrates says that anyone who makes a correct judgment will turn out to have combined it together with its account. Hence, correct judgment without knowledge will not be found anywhere. The second possibility is that an account means that a man has knowledge of a thing when he believes that same thing to be part of one thing or part of something else, or when he judges that one thing or some thing different that belongs to the same object. Socrates gives the example, that when a student is learning to write and is asked to spell Theaetetus’ name, the student thinks and then begins to write THE. When asked to write Theodorus’ name, he thinks and then starts with TE. If this is the case, Socrates asks, can it be said that the student knows the first syllable of Theaetetus’ name? Theaetetus answers that anyone at that age does not have the knowledge of spelling the name correctly. So this young person is writing with correct judgment but without knowledge. Hence, the person is writing while possessing an account along with correct judgment. This dichotomy is an instance of correct judgment with an account that cannot be called knowledge. Such a conclusion brings Socrates to his third possibility. A person could be able to mark an object with the characteristic by which it differs from all other similar objects. Theaetetus asks for an example of this condition. Socrates offers the sun as such an example, and asks whether Theaetetus would be satisfied if he were to say it is the brightest body that moves about the earth and the heavens. The point is that, if someone can get at a difference that distinguishes a thing from everything else, then that contrast provides an account of that thing. Socrates gives another example of someone looking at a shadow painting. Anyone close up to the painting cannot take it all in with a single view, but if the observer stands back, the picture will appear to have some meaning. Putting it another way, Socrates proffers the theoretical situation in which he forms a correct judgment about Theaetetus if he can also grasp Theaetetus’ account, then he can say that he knows Theaetetus. If he cannot understand Theaetetus’ account, then he is merely judging a young man. An account is a matter of showing differences. So Socrates would have to know some features that belong to Theaetetus only, such as the shape of his nose. For someone to say that it is Theaetetus who is before him, he must know these definite features about him to make such judgment. Thus, correct judgment is also concerned with differences in what the judgment is about. This type of reasoning goes round in circles because the answer to the question of “what knowledge is” is “correct judgment accompanied by knowledge of differences.”

Socrates says that, in the final analysis, knowledge is not perception, nor is it true judgment, nor an account added to judgment. What knowledge is remains an unresolved question. Socrates advises Theaetetus that he will be a better person as a result of this inquiry, but he must be modest and not think that he knows what he does not know. Socrates admits that he does not know any of the things that other men claim to know. In utter frustration Socrates concludes that all they have produced is “wind-eggs.” After this discussion he takes leave of Theaetetus to go to court to hear the indictment that Meletus has brought against him.