What Makes You You? 是什麼讓你是你？

🔊The oldest answer is that you are a soul, an immaterial thing that stays the same while body and mind change around it. Plato held this, and Descartes gave it its modern form: I am a thinking substance. The view has the advantage of giving a definite answer in every case. Its weakness was pointed out by Locke. A soul, as the theory describes it, has no features by which it could be recognized. If the soul in your body were replaced each night by another exactly like it, carrying the same memories, neither you nor anyone else would notice. A soul that makes no difference to anything we can observe cannot be what we mean when we say that this is the same person we met last year.

最古老的答案是：你是一個靈魂，一個非物質的東西；身體與心智在它周圍變化，它自己保持不變。柏拉圖這樣主張，笛卡兒給了它現代的形式：我是一個思考的實體。這個看法的好處是，在每一個情況下都給出確定的答案。它的弱點是洛克指出的。照這個理論的描述，靈魂沒有任何可供辨認的特徵。假如你身體裡的靈魂每天夜裡都被另一個一模一樣、帶著同樣記憶的靈魂換掉，你不會察覺，別人也不會。一個對我們所能觀察的一切都毫無差別的靈魂，不可能是我們說「這是我們去年見過的同一個人」時所指的東西。

🔊A second answer is that you are a living human animal. You are the same person as the child because you are the same organism, which has grown and replaced its matter as organisms do. This view, now called animalism, fits what biology tells us, and it explains why we identify one another by faces and fingerprints. Locke’s objection to it has convinced most readers since. “Should the soul of a prince, carrying with it the consciousness of the prince’s past life, enter and inform the body of a cobbler,” everyone sees, he says, that the person who wakes in the cobbler’s bed is the prince. He remembers the palace and is “accountable only for the prince’s actions.” A modern version puts a brain in place of the soul. If your brain were transplanted into another body, most people judge that you would go where the brain goes. If so, we are not simply our bodies.

第二個答案是：你是一個活著的人類動物。你跟那個孩子是同一個人，因為你們是同一個有機體；它像一切有機體那樣長大，並且更換了自己的物質。這個看法現在稱為「動物論」；它符合生物學告訴我們的事，也解釋了我們為什麼靠臉孔與指紋辨認彼此。洛克對它的反駁，說服了此後大多數的讀者。他說：「假如一位王子的靈魂，帶著對王子過去生活的意識，進入並主宰了一個鞋匠的身體」，那麼每個人都看得出來，在鞋匠床上醒來的那個「人」是王子。他記得宮殿，而且「只須為王子的行為負責」。現代的版本把靈魂換成了腦。如果你的腦被移植到另一個身體裡，多數人判斷：腦去哪裡，你就去哪裡。若是如此，我們就不單純是自己的身體。

🔊Locke’s own account was the first to locate identity in the mind’s contents. A person, he says, is “a thinking intelligent being, that has reason and reflection, and can consider itself as itself, the same thinking thing, in different times and places.” What makes a later person the same as an earlier one is consciousness reaching back: I am whoever I can remember being. The proposal was brilliant, and two objections were raised at once. Thomas Reid imagined a brave officer who remembers being flogged as a boy, and who later, as an old general, remembers his deeds as an officer and has forgotten the flogging. By Locke’s test the general is the officer and the officer is the boy, and the general is not the boy, which breaks the logic of identity. Bishop Butler added that memory cannot make me the same person, because it assumes that I am. To remember doing something, as opposed to merely seeming to, I must be the one who did it.

洛克自己的說法，是第一個把同一性放在心靈內容裡的。他說，一個「人格者」是「一個會思考、有智能的存在者，有理性與反省，並且能夠在不同的時間與地點，把自己當作自己，當作同一個思考的東西」。使後來的人與先前的人同一的，是往回延伸的意識：我記得自己曾經是誰，我就是誰。這個提議很高明，而立刻就有人提出了兩個反駁。里德設想了一位勇敢的軍官：他記得自己小時候挨過鞭打；後來他成了老將軍，記得自己當軍官時的事蹟，卻忘了那次鞭打。照洛克的檢驗，將軍就是軍官，軍官就是那個男孩，而將軍卻不是那個男孩；這就破壞了同一性的邏輯。巴特勒主教補充說：記憶不可能使我成為同一個人，因為它預設了我是。要「記得」做過某件事，而不只是「好像記得」，我就必須是做了那件事的人。

🔊Later philosophers repaired the theory. They replaced direct memory with overlapping chains of memory, and added the other connections that make up a mental life: intentions carried out, beliefs and character that persist. On the repaired view you are the child because a continuous series of such links runs from the child to you. This is the psychological continuity theory, and for most of the twentieth century it was the leading account.

後來的哲學家修補了這個理論。他們把「直接的記憶」換成「彼此重疊的記憶鏈」，並且加上構成一個心智生命的其他連結：被執行的意圖、持續下去的信念與性格。照修補後的看法，你是那個孩子，因為有一串連續的這類連結，從那個孩子一直通到你。這就是「心理連續論」；在二十世紀的大部分時間裡，它是領先的說法。

🔊In 1984 the Oxford philosopher Derek Parfit described a machine that puts the leading account under strain. You step into a booth on Earth. A scanner records the state of every cell in your body and, in doing so, destroys it. The information is sent to Mars, where a machine builds an exact replica out of local matter. The person who steps out on Mars has your memories, your character, and your plans, and believes that he has just made the journey. On the psychological theory this is you, and teleportation is a way of traveling.

1984 年，牛津的哲學家帕菲特描述了一台機器，讓這個領先的說法吃緊。你走進地球上的一個小艙。掃描器記錄下你身體每一個細胞的狀態，並且在掃描的同時把它毀掉。資訊被傳到火星，那裡的機器用當地的物質造出一個一模一樣的複製體。在火星走出艙門的那個人，有你的記憶、你的性格、你的計畫，並且相信自己剛剛完成了這趟旅程。照心理連續論，這就是你，而傳送是一種旅行的方式。

🔊Now suppose the scanner is improved so that it no longer destroys the original. You step out of the booth on Earth, and a moment later you are speaking by video to someone on Mars who looks and thinks exactly as you do. Nobody believes that the two of you are one person. Yet the replica stands in exactly the same relation to you as before. Everything that made the first case a journey is still present. What is new is only that you have also survived in the ordinary way. If the replica is not you in the second case, it is hard to see how it was you in the first, and then the first case was a death. And if you decide that it was a death, you have to say why the copying of everything you value about yourself should count for nothing.

現在假設掃描器改良了，不再毀掉原本的那個。你走出地球上的小艙，片刻之後，你正透過視訊跟火星上的某個人說話，他的長相與想法跟你一模一樣。沒有人相信你們兩個是同一個人。然而，那個複製體跟你的關係，跟先前完全一樣。使第一種情況成為「旅行」的一切，全都還在。新增的只有一點：你也以平常的方式存活了下來。如果在第二種情況裡複製體不是你，就很難看出在第一種情況裡它怎麼會是你；那麼第一種情況就是一次死亡。而如果你判定那是一次死亡，你就必須說明：你看重自己的一切都被複製過去了，為什麼這件事毫無分量？

🔊Parfit’s conclusion was radical. He argued that in these cases there is no further fact about whether the resulting person is me. We know everything there is to know once we know what happens to the body and how the mental states are connected. The question “But will it be me?” has no answer, and what is more surprising, it does not need one. What I have reason to care about is that there will be someone whose mental life continues mine, and that holds in the teleporter case whether or not we call it survival. Identity, he said, is not what matters. He reported that believing this changed his life. He had seemed to himself to be moving through a glass tunnel toward death, and afterward, he wrote, “the walls of my glass tunnel disappeared. I now live in the open air.”

帕菲特的結論很激進。他論證，在這些情況裡，對於「結果出現的那個人是不是我」，並沒有進一步的事實。一旦我們知道身體發生了什麼、心理狀態之間怎麼連結，我們就知道了所有可知的事。「可是那會是我嗎？」這個問題沒有答案；而更令人意外的是，它並不需要答案。我有理由在乎的是：將來會有一個人，他的心智生命延續著我的；而在傳送機的情況裡，不管我們稱不稱之為「存活」，這一點都成立。他說：重要的不是同一性。他說，相信這一點改變了他的人生。他原本覺得自己像是在一條玻璃隧道裡走向死亡；後來，他寫道：「我那條玻璃隧道的牆消失了。我現在活在露天之中。」

🔊The Western debate assumes that the self is something inside one person, and asks what it is. Classical Confucian thought starts somewhere else. A person is first of all a son or daughter, a parent, a friend, a subject or a minister, and to be good is to be these things well: “let the ruler be a ruler, the minister a minister, the father a father, the son a son.” On this view what I am cannot be stated without mentioning other people, and a human being with no relationships would be missing most of what makes a person. Zhuangzi goes further in the other direction. One of his characters comes out of a trance and says, “Just now I lost myself” (今者吾喪我). The Chinese uses two different words for “I,” and commentators have long taken the sentence to distinguish the self that we construct and defend from whatever it is that is left when that construction is dropped.

西方的辯論預設自我是一個人「裡面」的某個東西，然後問它是什麼。古典儒家思想從別的地方出發。一個人首先是兒子或女兒、父母、朋友、臣民或大臣；而做個好人，就是把這些身分做好：「君君，臣臣，父父，子子。」照這個看法，「我是什麼」不提到別人就說不出來；一個沒有任何關係的人，會缺少使人成為人的大部分東西。莊子往另一個方向走得更遠。他筆下的一個人物從出神的狀態回來，說：「今者吾喪我。」這句中文用了兩個不同的「我」字；歷來的註家認為，這句話區分了我們建構並捍衛的那個自我，以及把這個建構放下之後剩下的不管什麼東西。

🔊These puzzles are sometimes dismissed as science fiction. Their consequences are practical. When a person with advanced dementia no longer remembers her own life, families ask whether the wishes she wrote down years ago still bind, and the answer depends on whether she is the same person who wrote them. When a crime comes to trial forty years late, we ask whether the old man in the dock should be punished for what the young man did. Every promise assumes that the one who keeps it will be the one who made it. And each of us is concerned about one death in particular. If Parfit is right, that concern attaches to something less sharp-edged than we suppose. If he is wrong, there is some further thing that makes you you, and after two and a half thousand years of looking nobody has yet said convincingly what it is.

這些謎題有時被當成科幻小說打發掉。它們的後果是很實際的。當一位重度失智的人不再記得自己的一生，家屬會問：她多年前寫下的意願還有沒有約束力？而答案取決於她是不是寫下那些意願的同一個人。當一樁罪行遲了四十年才受審，我們會問：被告席上的老人，該不該為那個年輕人做的事受罰？每一個承諾都預設：履行承諾的人，將是許下承諾的人。而我們每一個人，都特別關切某一個人的死亡。如果帕菲特是對的，這份關切所附著的東西，沒有我們以為的那麼輪廓分明。如果他錯了，那麼就另有某個東西使你成為你；而找了兩千五百年，還沒有人令人信服地說出它是什麼。