Dear Nathaniel, Here's the whole thing. I've revised my discussion of Plato and added the notes about Epicurus. I'll possibly make more revisions in the next few days. Please email any questions or corrections or telephone if you prefer. Don't copy and paste; express ideas in your own words and they're yours. An idea expressed in your own words is your idea. Yoyo The question ============ "Compare Plato's theory of knowledge as he sets it out in Book V of the Republic with Epicurus' theory of knowledge. Consider what the objects of knowledge are, and what the source(s) of objectivity of knowledge are in each theory. Evaluate the theories on the basis of your comparison." Plato's Theory of Knowledge from Book V ======================================= Plato's theory of knowledge from Book V of the Republic is best summarized by his own words, or more accurately, by the words of his translator: > I said: 'Until philosophers are kings, or the kings and princes of this > world have the spirit and power of philosophy, and political greatness > and wisdom meet in one, and those commoner natures who pursue either > to the exclusion of the other are compelled to stand aside, cities > will never have rest from their evils,--nor the human race, as I > believe,--and then only will this our State have a possibility of life > and behold the light of day.' Such was the thought, my dear Glaucon, > which I would fain have uttered if it had not seemed too extravagant; > for to be convinced that in no other State can there be happiness > private or public is indeed a hard thing. Knowledge is considered from other perspectives in the dialogues Theatetus, Parmenides and in Sophist. In the Republic, concerned as Plato is with the design of the perfect state, Plato identifies a philosophical spirit to be the essential prerequisite of society's rulers. Since in the Republic the ruler is to be a philosopher, Plato takes the occasion to define what a philosopher is: > And may we not say of the philosopher that he is a lover, not of a part > of wisdom only, but of the whole? However, there are many individuals who are curious and who take pleasure in learning, who are not true philosophers: > Glaucon said: If curiosity makes a philosopher, you will find many a > strange being will have a title to the name. All the lovers of sights > have a delight in learning, and must therefore be included. Musical > amateurs, too, are a folk strangely out of place among philosophers, for > they are the last persons in the world who would come to anything like > a philosophical discussion, if they could help, while they run about at > the Dionysiac festivals as if they had let out their ears to hear every > chorus; whether the performance is in town or country--that makes no > difference--they are there. Now are we to maintain that all these and > any who have similar tastes, as well as the professors of quite minor > arts, are philosophers? > He said: Who then are the true philosophers? > Those, I said, who are lovers of the vision of truth. To be a true philosopher one must love not only learning, but one must love a vision of the truth. > And this is the distinction which I draw between the sight-loving, > art-loving, practical class and those of whom I am speaking, and who are > alone worthy of the name of philosophers. Just as there are lovers of learning who are not lovers of the absolute vision of the truth, so there are lovers of beautiful things who are not lovers of absolute beauty. > The lovers of sounds and sights, I replied, are, as I conceive, fond of > fine tones and colours and forms and all the artificial products that > are made out of them, but their mind is incapable of seeing or loving > absolute beauty. > And he who, having a sense of beautiful things has no sense of absolute > beauty, or who, if another lead him to a knowledge of that beauty is > unable to follow--of such an one I ask, Is he awake or in a dream > only? Reflect: is not the dreamer, sleeping or waking, one who likens > dissimilar things, who puts the copy in the place of the real object? > But take the case of the other, who recognises the existence of absolute > beauty and is able to distinguish the idea from the objects which > participate in the idea, neither putting the objects in the place of the > idea nor the idea in the place of the objects--is he a dreamer, or is he > awake? Plato's juxtaposition of truth and beauty is reminiscent of John Keats' Ode on a Grecian Urn. "Beauty is truth, truth beauty, that is all Ye know on earth, and all ye need to know." Keats goes farther than Plato, at least in Book V of the Republic. where truth and beauty are equated only implicitly. The conflation of truth and beauty is significant for Plato inasmuch as it defines, and perhaps secures the absolute, the unconditional, as an anchor for both truth and beauty. Absolute beauty is a vision if anything more compelling than the notion of absolute truth, and the two would tend to buttress each other, at least in the mind of the nineteenth century romantic idealist, and it seems not too far fetched to suggest that these notions provided reciprocal support to each other in Plato's intellectual experience as well. Truth is the product of knowledge; beauty is the product of perception. If truth and beauty have a common factor in their absolute nature, it is reasonable to inquire whether knowledge as a source of truth and perception as the source of physical beauty might also have a factor in common. Arguably, knowing (knowledge) might be related to truth as feeling (sensation) is related to beauty. Let's ask Epicurus. Significantly, Plato makes no claim that the arguments in the 5th book of the Republic are the absolute truth which he extols. On the contrary the term that Socrates uses to state his ideas is "doxein", "it seems to me" rather than I know or I am certain. Glaucon then parrots him, saying "It's true." This is an example of Socrates being the midwife. Truth is nascent within Glaucon's mind like the fetus in the womb. Socrates is forever asking what the lawyers call leading questions: "It seems to me that ..." or "Isn't is true that ..." In an American courtroom that kind of coaching is permitted only of a hostile witness. But Glaucon is the friendliest witness imaginable. In an American courtroom, the judge would sneer at Socrates' eristics, and would tell him to go back to law school and learn that while leading questions are o.k. on cross-examination, on direct examination leading questions are taboo. (A leading question is a question which suggests the answer.) The question and answer session of which Chapter V is a typical example is a demonstration of Socrates Theory of Knowledge in action, a theory which Plato in effect endorses with the structure and style of his dialogue. Truth is hidden within Glaucon; Socrates is the midwife who helps Glaucon bring the truth within him to light and to life. The Republic Book V discussion of who is a philosopher illustrates yet another facet of Plato's Theory of Knowledge. In other dialogues, Gorgias, Protagoras and/or Theatetus. Socrates is explicitly critical of the sophists' style of purporting to display truth in "long speeches" (makroi logoi) whereas he, Socrates, prefers the question and answer approach. Consider this distinction between the long speech and the question and answer method of demonstrating knowledge in the light of our familiar dual use of the term "knowing": we speak of knowing THAT and we speak of knowing HOW. I "know" THAT a conductor stands in front of a musical orchestra and waves his arms with a baton in his hand. You know HOW to conduct. The sophist with his long speech presumes to TELL us about knowledge. Socrates with his questions and answers presumes to SHOW us how to know. When Socrates shows us how to know, he offers us knowledge by indirection. He points to knowledge; he does not disclose knowledge. Each person must find knowledge for him or herself. Socrates tells us to recognize knowledge by its being unconditional and absolute, but unlike the sophist who sells knowledge as if it were produce, Socrates does not even presume to give it away. ==> (The foregoing ideas possibly go (far) beyond what your teacher had in mind; and when you present your teacher with something he or she has never thought of, you run the risk of being put down with a bad grade. As you compose your essay, keep your teacher's mental disposition in mind. I have found that sometimes the smartest procedure is to keep the smartest ideas to oneself. ) Knowledge attains to truth and describes "being", describes what is real. Ignorance finds only falsehood, and what it describes does not exist. Between knowledge and ignorance there is an intermediate, doxa, which is translated as opinion, but which could also be translated as "seeming", that which seems to be real but is not. > And may we not say that the mind of the one who knows has knowledge, and > that the mind of the other, who opines only, has opinion? > Then knowledge and opinion having distinct powers have also distinct > spheres or subject-matters? > Being is the sphere or subject-matter of knowledge, and knowledge is to > know the nature of being? > And opinion is to have an opinion? > Then you would infer that opinion is intermediate? > But were we not saying before, that if anything appeared to be of a sort > which is and is not at the same time, that sort of thing would appear > also to lie in the interval between pure being and absolute not-being; > and that the corresponding faculty is neither knowledge nor ignorance, > but will be found in the interval between them? > Then what remains to be discovered is the object which partakes equally > of the nature of being and not-being, and cannot rightly be termed > either, pure and simple; this unknown term, when discovered, we may > truly call the subject of opinion, and assign each to their proper > faculty,--the extremes to the faculties of the extremes and the mean to > the faculty of the mean. Opinion addresses something whose existence is uncertain, which sometimes seems to be and sometimes seems not to be. Again Plato resorts to esthetics, to his notion of beauty to make himself clear: > This being premised, I would ask the gentleman who is of opinion that > there is no absolute or unchangeable idea of beauty--in whose opinion > the beautiful is the manifold--he, I say, your lover of beautiful > sights, who cannot bear to be told that the beautiful is one, and the > just is one, or that anything is one--to him I would appeal, saying, > Will you be so very kind, sir, as to tell us whether, of all these > beautiful things, there is one which will not be found ugly; or of the > just, which will not be found unjust; or of the holy, which will not > also be unholy? Note that the singularity of beauty is inconsistent with esthetic experience. (Bach is not Mozart, yet both are "beautiful".) The purported singularity of beauty is an inference from logic, an inference from language. Plato's idealism is the reification of language, the translation of words into things. > No, he replied; the beautiful will in some point of view be found ugly; > and the same is true of the rest. > Thus then we seem to have discovered that the many ideas which the > multitude entertain about the beautiful and about all other things are > tossing about in some region which is half-way between pure being and > pure not-being? > Yes; and we had before agreed that anything of this kind which we might > find was to be described as matter of opinion, and not as matter of > knowledge; being the intermediate flux which is caught and detained by > the intermediate faculty. > Then those who see the many beautiful, and who yet neither see absolute > beauty, nor can follow any guide who points the way thither; who see the > many just, and not absolute justice, and the like,--such persons may be > said to have opinion but not knowledge? > That is certain. > But those who see the absolute and eternal and immutable may be said to > know, and not to have opinion only? > Neither can that be denied. > The one love and embrace the subjects of knowledge, the other those of > opinion? The latter are the same, as I dare say you will remember, who > listened to sweet sounds and gazed upon fair colours, but would not > tolerate the existence of absolute beauty. > Yes, I remember. > Shall we then be guilty of any impropriety in calling them lovers of > opinion rather than lovers of wisdom, and will they be very angry with > us for thus describing them? > But those who love the truth in each thing are to be called lovers of > wisdom and not lovers of opinion. What Plato's knowledge of truth, apperception of beauty, and determination of justice have in common is certainty, immutability, reliability, absence of contingency or dependence on accident. It is a matter of elementary experience that our perception of the world, - what we see, what we hear, what we remember, waxes and wanes, fluctuates and fades, according to Plato a world of seeming rather than being, a world apprehended not by knowledge but by opinion. What is absolute, what is unchanging, what is infinitely more dependable than opinion, perception and sensation are the symbols with which our minds tag our experiences; it is the logos, the word, which represents our idea which is the emblem of Platonic truth. This circumstance was expressed most eloquently by the Platonist who wrote the Gospel of St. John. "In the beginning was the Word, and the Word was with God, and the Word was God." =============================== Epicurus' Theory of Knowledge: A discussion of Epicurus theory of knowledge presents special problems which we should not overlook. I haven't done research on this topic, but it's my impression that few if any of Epicurus' writings have been preserved, and that our understanding of him, such as it is, derives from Diogenes Laertius who compiled histories of the lives of the ancient philosophers. Kant famously said that the history of philosophy is not philosophy, only to contradict himself by positioning himself in the history of philosophy as the Copernicus of thought. I don't need to convince you that the history of music (musicology) is not the same as music. Music is yourself picking up your trumpet and playing! The history of music is the story of other musicians at times past in distant places picking up their trumpets and playing. I don't need to tell you that the only music which is real for you, is the music that YOU play. Similarly, the only thought that is true for you, is the thought that YOU think. Thus we must accept the fact that Diogenes Laertius is a filter through which we learn about Epicurus. We must accept the circumstance that Diogenes Laertius filters out everything about Epicurus that Diogenes himself doesn't understand, and that what Diogenes is able to report is unavoidably distorted by his own (mis)conceptions. And that's not the worst of it. Even more problematic is Diogenes' language which as I read it is very different from the Greek of Plato and Aristotle, and is replete with terms about the meaning of which I can't be sure. Can I be sure that the translator was sure? that he envisioned the pure truth when he translated "prolepsis" as "preconception" (= basic grasp). If the translator didn't know what Epicurus meant by prolepsis, is the synonym preconception of any help? What's the difference between the "preconception" of Epicurus and the Form, Ideal or Idea of Plato? Finally, I have reservations about purporting to evaluate Epicurus' theory of knowledge remote from the context of what Epicurus himself knew or purported to know, independent of Epicurus' own esthetic, ethical and cognitive experience, independent of the world in which Epicurus understood himself to live. But an assignment is an assignment, and if the teacher demands "the pure truth" or even a mere "seeming opinion" about Plato and Epicurus before the Christmas Holidays, you and I will have to do our best. In the end the teacher will get what he or she asked for. ======================= Plato was perplexed by the fallibility and evanescence of sensory perception. Truth, Plato thought, can't be here today and gone tomorrow. That's why he put his faith in the idea. Epicurus understood that Plato's ideas are empty and argued, that as a basis of knowledge, sense-perception which fades is better than an idea which is perfect and pure but empty. It's helpful, I think, perhaps even essential, to consider specific sense perceptions rather than to pontificate in generalities. If I remember correctly, traditionally there is a count of five senses: vision, hearing, taste, smell and touch. I don't know the provenance of this list, - possibly Aristotle, but I won't take time to look it up. Modern neurophysiology holds that taste and smell are mediated by the same neuronal pathways and should be considered together. Touch, on the other hand, is more complex: the neurologist tests it by pricking his patient with needles, tickling him with a cotton applicator, indenting the skin with a smooth blunt dowel, grasping and moving a toe, a finger, a leg or an arm, to ascertain whether the patient can perceive the motion and the position of the limb. That's called kinesthesia and proprioception. We must assume that the sense-perceptions to which Epicurus refers correspond to the sense perceptions of our experience. Here's what Epicurus is reported to have said about sense-perceptions. > Epicurus: Diogenes Laertius, Lives of the Philosophers, 29-34 > Now, in the Canon, Epicurus says that the criteria of truth are > the sense-perception, and the preconceptions (= basic grasps), > and the feelings. > But the Epicureans, in general, > add also the application of the intellect to presentations. > And he says the same thing in his Epitome, > which he addresses to Herodotus, > and also in his Principal Doctrines. > For, he says, the sense-perceptions are devoid of reason, > nor can they remember. Devoid of reason: obviously: there are many visual stimuli which the patient cannot interpret. So he goes to the eye doctor and says: Doctor, I see flashes of light, like lightning around the periphery of my visual field. I don't know what's going on. Obviously a sense-perception devoid of reason. Says the doctor: you have vitreous separation. That's a hundred dollars. Do you have insurance? Otherwise, your credit card number, please. Devoid of reason, in other ways. I see an object on the horizon, don't know what it is: a house, a grove of trees, an outcropping of granite or basalt? I won't know until I get closer, or someone tells me. Devoid of reason, also: I hear a sound? Was that the radio, or did you say something? I didn't understand, speak louder, please and more distinctly. Reason arrives only later, with my understanding. > nor can they remember. Obviously not. Imagine yourself sitting at a window gazing into darkness. A flash or light! You see the landscape, the tree, the house across the street. As soon as it's dark, the image is gone. (There may be in fact a faint afterimage, but that's worse than useless, tells you nothing. Can't remember a sound either, when the final chord of the symphony ends, it's gone, for good. And even worse, the god-awful applause drowns all memory of it. (I think it quaint, how Beethoven can't accept an ending to his music, and repeats the final chord of the symphony over and over again as if he wanted it to ring forever.) > Nor is there anything that can refute sense-perception. An image is an image, a sound is a sound; they are there, you can't argue with them, and if you can't argue with them, you can't refute them. > For they are not by themselves the cause of any motion, An allusion, I believe to the notion that motion (action) is a consequence of the will, that it's the conscious mind which makes the body to move. That's a mistake, but I'll pass over it. > and when they have received any presentation from any external cause, > then they can add nothing to it, > nor can they subtract anything from it. > Moreover, they are out of the reach of any control. An individual has no control over his perceptions. He is at their mercy. Nothing can alter them or change the perceptions. This is true, once the sense-perceptions prevail. Obviously, sense-perceptions, absent in sleep, will be modified by alcohol or opium, but such modification is extrinsic rather than inherent in the sense-perceptions themselves. > 32. For a perception from one sense > can't refute another of the same type; > for they have all an equal value. > Nor can one judge of another which is different from itself; > since their objects are not identical. > In other words, one perception cannot control another, > since the effects of all of them influence us equally. > Again, Reason can't pronounce on the senses; > for we have already said that all reasoning > has the senses for its foundation. In the foregoing sentences Epicurus is trying to establish the autonomy of the senses and their independence of reason. The putative autonomy of the sense is a matter of intuition which, even though not necessarily valid, is not subject to controversy. The argument, however, that the senses are independent of reason, is circular. The identification and the description of the senses, and of sense-perception as such is in itself an accomplishment of reason, and although reasoning has the senses for its foundation, the absence of reason would make meaningless both the existence and the function of the senses. > Reality and the evidence of perception > establish the certainty of the senses; I think that what is claimed is that reality and the evidence of perception establish the certainty of that which the senses reveal. The argument is circular: If the senses reveal reality, then reality can't validate the senses; because if the senses are faulty the reality they reveal will similarly be faulty. > for the presentations of sight and hearing are just as real, > just as evident, as pain. On this point, there is no disagreement. > It follows from these considerations > that we ought to judge of things which are obscure > by their analogy to those which we perceive directly. > In fact, every notion proceeds from the senses, > either directly, or in consequence of some analogy, > or proportion, or combination; > reasoning having always a share in these last operations. The foregoing is valid only if the nets of analogy, proportion or combination are cast wide enough. Narrowly construed, there are obviously many notions that do not proceed from the senses but from the symbolic forms with which reason mimics the senses. > The visions of insanity and of sleep > have a real object for they act upon us; > and that which has no reality can produce no action. The foregoing three lines are inventions of the translator. A more accurate translation is > The phantasms of insanity and the truths of sleep > cause motion. That which is not does not cause motion. The concept of "object" in this context was alien to Epicurus. > 33. By preconception, > the Epicureans meant a sort of comprehension as it were, > or right opinion, or notion, or general idea which exists in us; > or, in other words, > the recollection of an external object often perceived anteriorly. > Such for instance, is the idea: "Man is being of such and such nature." > At the same moment that we utter the word man, > we conceive the figure of a man, > in virtue of a preconception which we owe > to the preceding operations of the senses. > Therefore, the first notion which each word awakens in us is a correct one; > in fact, we could not seek for anything > if we had not previously some notion of it. > To enable us to affirm that what we see at a distance is a horse or a cow, > we must have some preconception in our minds > which makes us acquainted with the form of a horse and a cow. > We could not give names to things, > if we had not preliminary notion of what the things were. > These preconceptions then furnish us with certainty. > And with respect to judgments, > their certainty depends on our referring them to some previous notion, > of itself certain, in virtue of which we affirm such and such a judgment; > for instance, "How do we know whether this thing is a man?" A loyal disciple of Plato couldn't have made a more cogent and persuasive argument for Plato's theory of forms which seems to me to be universally confirmed by clinical psychology. Here's the story as I understand it: The human mind is shaped by the impressions that act upon it. A child with congenital cataracts, will never distinguish objects if the cataracts are removed only after it has become an adult. A child who is deaf, will never learn to speak. To please those with a prejudice in favor of physics, who as Plato said somewhere, consider real only what they can touch with their hands, it is quite reasonable to postulate that just as the human skin adapts to ultraviolet stimulation by developing melanophores and turning dark, so the human mind adapts itself to the myriad of sensory stimuli which impinge on it, that these stimuli cause biochemical changes in the nervous system which enable the creature to adapt to the environment and survive. Among such stimuli should be reckoned the widest spectrum of experience, from learning to orient oneself in a hitherto foreign landscape which now becomes familiar, learning ones native language, and later on the language taught in college, acquiring all manner of psychomanual skills, from playing the trumpet to polishing shoes. Learning is adaptation of the mind and produces more or less permanent patterns of thought which Plato refers to as ideals or forms. > 34. The Epicureans also refer to "opinion" as supposition. > And say that it is at times true, and at times false; > for that, if it is supported by testimony, > and not contradicted by testimony, then it is true; > but if it is not supported by testimony, > and is contradicted by testimony, then it is false. > On which account they have introduced the expression of "waiting," > as if, before pronouncing that a thing seen is a tower, > we must wait till we come near, > and learn what it looks like when we are near it. In the preceding argument, it seems to me, Epicurus also closely follows Plato. The Socrates of the dialogues, as I have pointed out, lives in a world of appearances about which he expresses opinions with which he challenges his pupils. In the process of dialogue the mind comes closer to truth just as does the traveler when he comes to recognize the distant tower for what it is. > They say that there are two feelings, pleasure and pain, > which affect everything alive. > And that the one is natural, > and the other foreign to our nature; > with reference to whichs > all objects of choice and avoidance are judged of. The notion that pain is foreign to human nature is a hedonistic fallacy. Pain is an indispensable indicator of danger which protects the creature from serious injury and death. ========================= "Compare Plato's theory of knowledge as he sets it out in Book V of the Republic with Epicurus' theory of knowledge." Plato's theory identifies the unconditional validity of an intellectual apperception as the criterion of truth. Plato is so discouraged by the fallibility of sense perception that he ignores sense perception as a source of knowledge, attributing true knowledge to the existence of innate ideals. For Epicurus the sensory perception is the source of opinion. Epicurus identifies as knowledge the progressive approximation of opinion to an ideal of truth whose existence is acknowledged only implicitly, inasmuch as the ideal is not attainable in practice. ========================= Consider what the objects of knowledge are, and what the source(s) of objectivity of knowledge are in each theory. For Plato the objects of knowledge are the Forms or Ideals which are innate to the soul of each individual. Knowledge resides within the individual, and the learning is the progressive recognition of the absolute truth which resides within the individual. The source of objectivity for Plato is the character of the ideal forms. Plato ignores the circumstance that the efficacy of the ideal forms derives from the circumstance that they are a distillate of the perceptions of the outside world which an individual accumulates throughout life. For Epicurus the objects of knowledge are the sensory perceptions which are modified by prolepsis or preconceptions. Such preconceptions, when valid, are confirmed by sense perceptions are they accumulate. If one accepts Epicurean preconceptions as equivalent to Platonic Forms, then the difference between the two theories of knowledge becomes largely a matter of emphasis, but not entirely so, inasmuch as Plato fails to acknowledge the role of sense perception in shaping the ideal form and its correspondence to reality. =========================== Evaluate the theories on the basis of your comparison." Although the epistemology of Epicurus, empirical as it is, would on first consideration seem to be corroborated by modern science, closer scrutiny will uncover serious deficiencies. Sense perception is an eminently individual and subjective experience. You cannot feel my pain. I cannot see your visions. I cannot hear the voices that incite you to action. In order for you and me to be in communication, we must establish a common symbolic language, both verbal and mathematical. We must be able to converse in words and concepts which possess an absolute integrity similar to that with which Plato endowed true knowledge. We must agree on an arithmetic and algebraic calculus with which we may make numerical models of our common experience. Although the seductive naivete of Epicurean sensationalism would entice us to repudiate Plato, sober review of our scientific heritage suggests that we cannot afford to jettison the Platonic ideal. From the physics of Galileo, Kepler, Copernicus and Newton to the relativity and quantum theories of contemporary physicists, to digital computer science, to the calculations on which modern technology and economics are based, all the logic, and all the mathematics which make the modern world go around are in essence expressions of Platonic ideals. Plato was a mathematician, and his epistemology as the framework for the ideal is the ultimate of mathematical and historical models. The characteristic of these models is their intrinsic symbolism. It is the symbolic nature of language and of mathematics which accounts for their unlimited communicability. Platonic idealism implemented in the symbolic theories of science is indispensable to the communal intellectual effort which constitutes the human achievement of at least the past two millenia. Plato's theory is not perfect. It lacks the psychological link to experience and sense perception. But that link can be readily improvised by an empirical psychology. Epicurean sensationalism, on the other hand, leads into a blind alley of intellectual and spiritual isolation. It seeks to escape from its ghetto on the ladder of prolepsis or preconception, and where it succeeds, it finds itself playing catch-up in the groves of Platonic academe.