Is Seeing Believing? 眼見為憑嗎？

🔊Picture people living in an underground cave whose long entrance is open to the daylight. “Here they have been from their childhood, and have their legs and necks chained so that they cannot move, and can only see before them.” Behind and above them a fire is burning. Between the fire and the prisoners runs a raised path with a low wall along it, like the screen at a puppet show, and along the path people carry statues and figures of animals, which stick up above the wall. The firelight throws the shadows of these figures on the wall of the cave in front of the prisoners.

想像有一群人住在地下的洞穴裡，洞穴有一條長長的通道通向日光。「他們從小就在這裡，腿和脖子都被鍊住，所以不能移動，只能看見前面。」在他們背後的高處，有一堆火在燒。火與囚徒之間有一條墊高的路，路邊有一道矮牆，就像木偶戲的屏幕；有人沿著這條路，搬運人像與動物的造像，這些東西高出矮牆。火光把這些造像的影子，投在囚徒面前的洞壁上。

🔊The prisoners have never seen anything else. They give the shadows names, and they honor whoever is quickest at predicting which shadow will come next. If the carriers speak, the echo seems to come from the shadows. “To them,” Socrates says, “the truth would be literally nothing but the shadows of the images.” His companion remarks that these are strange prisoners. Socrates answers: “Like ourselves.”

囚徒從來沒有見過別的東西。他們替影子取名字，並且推崇最會預測下一個影子的人。如果搬運的人說話，回聲聽起來就像是從影子發出來的。蘇格拉底說：「對他們來說，真實簡直就只是那些造像的影子。」他的同伴說，這些囚徒真奇怪。蘇格拉底回答：「跟我們一樣。」

🔊Now suppose one prisoner is released and forced to stand up and turn around. The movement hurts, and the fire dazzles him. Told that what he sees now is more real than the shadows, he does not believe it, for the shadows were clear and these shapes are a blur. If he is then dragged up the steep, rough passage into the sunlight, he is at first unable to see anything at all. His eyes adjust by stages. He can look first at shadows, then at reflections in water, then at things themselves, then at the moon and stars by night. “Last of all he will be able to see the sun, and not mere reflections of him in the water.” He comes to understand that the sun produces the seasons and governs everything in the visible world, and that it is in some way the cause of all that he and his companions used to see.

現在假設有一個囚徒被鬆開，被強迫站起來、轉過身去。這個動作讓他疼痛，火光讓他目眩。有人告訴他，他現在看到的比影子更真實；他不相信，因為影子是清楚的，而這些形體一片模糊。如果接著他被人拖上那條陡峭崎嶇的通道，拉到陽光下，他起初什麼也看不見。他的眼睛是一階一階適應的。他先能看影子，然後是水中的倒影，然後是事物本身，然後是夜裡的月亮與星星。「最後他將能夠看見太陽，而不只是太陽在水中的倒影。」他終於明白，是太陽造成四季、主宰可見世界裡的一切，而且在某種意義上，它是他與同伴們過去所見一切的原因。

🔊Socrates explains the image himself. “The prison-house is the world of sight, the light of the fire is the sun,” and the journey upward is “the ascent of the soul into the intellectual world.” So the cave is the whole world that our senses reveal, and the world outside stands for what can be grasped only by thinking. The things out there are what Plato calls Forms: justice itself, beauty itself, the triangle that geometry studies, as opposed to this or that just act, beautiful face, or chalk drawing. The sun stands for the highest of them, the Form of the Good, which, he says, “appears last of all, and is seen only with an effort.”

蘇格拉底自己解釋了這個意象。「牢房就是視覺的世界，火的光就是太陽」，而向上的旅程是「靈魂上升到理智的世界」。所以洞穴就是感官向我們揭示的整個世界，洞外的世界則代表只有靠思考才能掌握的東西。外面的那些事物，就是柏拉圖所說的「理型」：正義本身、美本身、幾何學研究的那個三角形，而不是這個或那個正義的行為、美麗的臉孔、粉筆畫的圖。太陽代表其中最高的一個，「善的理型」；他說，它「最後才出現，而且要費力才看得見」。

🔊Why believe in such things? Plato’s main reason concerns knowledge. Whatever we perceive is changing, and it has its qualities only more or less: two sticks are equal from here and unequal from there, and a law is just in one city and unjust in another. Yet we do seem to know what equality and justice are, well enough to see that the sticks and the laws fall short. Plato concludes that knowledge must have objects of its own, stable and perfect, which particular things only resemble.

為什麼要相信有這種東西？柏拉圖的主要理由跟知識有關。我們感知到的一切都在變，而且它們具有某種性質，總是只到某個程度：兩根棍子從這裡看相等，從那裡看不等；一條法律在這個城邦是正義的，在另一個城邦是不義的。然而我們似乎確實知道相等與正義是什麼，而且知道得夠清楚，才看得出那些棍子與法律有所不足。柏拉圖的結論是：知識必定有它自己的對象，穩定而完美，個別事物只是與它們相似。

🔊The story does not end in the sunlight. The freed prisoner remembers the others and pities them, and he goes back down. His eyes, used to the sun, are now useless in the dark. He does badly at the shadow contests. “Men would say of him that up he went and down he came without his eyes,” and that the journey is not worth making. If anyone tried to free them and lead them up, Socrates adds, they would kill him if they could. Plato’s first readers knew whom he meant. Athens had put Socrates to death some twenty years before.

故事並沒有在陽光下結束。被釋放的囚徒想起其他人，憐憫他們，於是走回洞裡。他的眼睛習慣了太陽，現在在黑暗裡毫無用處。他在猜影子的比賽裡表現很差。「人們會說，他上去一趟，回來眼睛就壞了」，並且說這趟旅程根本不值得走。蘇格拉底又說，如果有人想解開他們、帶他們上去，他們要是辦得到，會把那個人殺掉。柏拉圖最早的讀者知道他指的是誰。雅典在大約二十年前處死了蘇格拉底。

🔊The return is also a duty. In Plato’s ideal city, those who have seen the Good are not allowed to stay above. “They must be made to descend again among the prisoners in the den, and partake of their labours and honours.” They would prefer to stay in the light, and Plato argues that this is exactly what fits them to govern.

回去同時也是一項責任。在柏拉圖的理想城邦裡，見過「善」的人不准留在上面。「必須讓他們再下到洞穴的囚徒當中，分擔他們的勞苦與榮譽。」他們寧可留在光裡；柏拉圖論證說，正是這一點，使他們適合治理城邦。

🔊Before he leaves the image, Socrates draws a conclusion about teaching that every teacher should know. Education is not what some people say it is, putting knowledge into a soul that lacks it, “like sight into blind eyes.” The power to learn “exists in the soul already.” What is needed is a turning around: “just as the eye was unable to turn from darkness to light without the whole body, so too the instrument of knowledge can only by the movement of the whole soul be turned from the world of becoming into that of being.” On this view a teacher transmits nothing. The teacher’s work is to arrange things so that the student turns and looks. The turning is uncomfortable, and the student may well resent the person who causes it.

在離開這個意象之前，蘇格拉底引出了一個關於教學的結論，每一位老師都該知道。教育並不是某些人說的那樣，把知識放進缺少知識的靈魂裡，「像把視力放進瞎了的眼睛」。學習的能力「本來就在靈魂之中」。需要的是一次轉向：「正如眼睛不連著整個身體就無法從黑暗轉向光明，認識的工具也只有藉著整個靈魂的運動，才能從生成變化的世界轉向存有的世界。」照這個看法，老師什麼也沒有傳遞。老師的工作是把事情安排好，讓學生轉過身去看。這個轉身並不舒服，而學生很可能怨恨促成它的那個人。

🔊Few philosophers now accept Plato’s Forms. His own pupil Aristotle argued that the form of a thing exists in the thing and cannot be found in a separate realm. But the cave has outlived the theory it was built to illustrate, because the situation it describes keeps recurring. People do mistake the images of things for things. Much of what anyone believes about the wider world was seen on a screen, arranged by people who remain out of sight behind a wall. And the story makes a point about method that does not depend on any theory of Forms. From inside the cave, the shadows are clear and the truth is a painful blur. So the vividness of an experience is no measure of its reality. Sight is good evidence, in other words, and it still has to answer to understanding.

現在很少有哲學家接受柏拉圖的理型。他自己的學生亞里斯多德就論證過，事物的形式存在於事物之中，在另一個分離的領域裡是找不到的。可是洞穴比它原本要說明的理論活得更久，因為它描述的處境不斷重現。人確實會把事物的影像誤認為事物。任何人對更大的世界所相信的事，有許多是在螢幕上看到的，而安排這些影像的人，始終躲在牆後、不在視線之內。而且這個故事提出了一個關於方法的論點，這個論點並不依賴任何理型論。從洞穴裡面看，影子是清楚的，真相是一片刺痛的模糊。所以一個經驗有多鮮明，並不能衡量它有多真實。換句話說，看見是好的證據，但它仍然得向理解負責。