公正：該如何做是好

編者按：這兩年，哈佛、耶魯?shù)葒庵髮W(xué)的公開課在網(wǎng)上異?；鸨?，不少國內(nèi)年輕人都曾經(jīng)通過互聯(lián)網(wǎng)觀看過。哈佛大學(xué)教授邁爾克·桑德爾的《公正》，又可以算得上是其中最受歡迎的課程。

桑德爾教授會在課堂上通過一些假設(shè)或真實(shí)案例的描述，置學(xué)生于倫理兩難困境中，然后要他們做出決定:“該如何做是好？”從而引導(dǎo)人們對公正和平等做出思考。

《公正》一課的精彩內(nèi)容已結(jié)集出版，這里選取的是《失控的電車》一節(jié)，此案例也是桑德爾教授在課程一開始就提出的問題。如果必須選擇殺死1人或者殺死5人，你會怎么選？在課堂上，有多數(shù)的學(xué)生投票來贊成殺死1人，來保全其余五個人的性命。但是桑德爾提出了三個類似的道德困境，當(dāng)學(xué)生站起來為自己的艱難抉擇辯護(hù)時，教授提出了他的觀點(diǎn)：我們的道德推理背后的假設(shè)往往是矛盾的，而什么是正確什么是錯的問題，并不總是黑白分明的。

《公正》是哈佛歷史上累計(jì)聽課人數(shù)最多的課程。

The Runaway Trolley

[1] Suppose you are the driver of a trolley car hurtling down the track at sixty miles an hour. Up ahead you see five workers standing on the track， tools in hand. You try to stop， but you can’t. The brakes don’t work. You feel desperate， because you know that if you crash into these five workers， they will all die. (Let’s assume you know that for sure. )

Suddenly， you notice a side track， off to the right. There is a worker on that track， too， but only one. You realize that you can turn the trolley car onto the side track， killing the one worker， but sparing the five.

What should you do? Most people would say， “Turn! Tragic though it is to kill one innocent person， it’s even worse to kill five. ” Sacrificing one life in order to save five does seem the right thing to do.

[2] Now consider another version of the trolley story. This time， you are not the driver but an onlooker， standing on a bridge overlooking the track. (This time， there is no side track. ) Down the track comes a trolley， and at the end of the track are five workers. Once again， the brakes don’t work. The trolley is about to crash into the five workers. You feel helpless to avert this disaster—until you notice， standing next to you on the bridge， a very heavy man. You could push him off the bridge， onto the track， into the path of the oncoming trolley. He would die， but the five workers would be saved. (You consider jumping onto the track yourself， but realize you are too small to stop the trolley. )

Would pushing the heavy man onto the track be the right thing to do? Most people would say， “Of course not. It would be terribly wrong to push the man onto the track. ”

Pushing someone off a bridge to a certain death does seem an awful thing to do， even if it saves five innocent lives. But this raises a moral puzzle: Why does the principle that seems right in the first case—sacrifice one life to save five—seem wrong in the second?

[3] If， as our reaction to the first case suggests， numbers count—if it is better to save five lives than one—then why shouldn’t we apply this principle in the second case， and push? It does seem cruel to push a man to his death， even for a good cause. But is it any less cruel to kill a man by crashing into him with a trolley car?

Perhaps the reason it is wrong to push is that doing so uses the man on the bridge against his will. He didn’t choose to be involved， after all. He was just standing there.

But the same could be said of the person working on the side track. He didn’t choose to be involved， either. He was just doing his job， not volunteering to sacrifice his life in the event of a runaway trolley. It might be argued that railway workers willingly incur a risk that bystanders do not. But let’s assume that being willing to die in an emergency to save other people’s lives is not part of the job description， and that the worker has no more consented to give his life than the bystander on the bridge has consented to give his.

[4] Maybe the moral difference lies not in the effect on the victims—both wind up dead—but in the intention of the person making the decision. As the driver of the trolley， you might defend your choice to divert the trolley by pointing out that you didn’t intend the death of the worker on the side track， foreseeable though it was; your purpose would still have been achieved if， by a great stroke of luck， the five workers were spared and the sixth also managed to survive.

But the same is true in the pushing case. The death of the man you push off the bridge is not essential to your purpose. All he needs to do is block the trolley; if he can do so and somehow survive， you would be delighted.

Or perhaps， on reflection， the two cases should be governed by the same principle. Both involve a deliberate choice to take the life of one innocent person in order to prevent an even greater loss of life. Perhaps your reluctance to push the man off the bridge is mere squeamishness， a hesitation you should overcome. Pushing a man to his death with your bare hands does seem more cruel than turning the steering wheel of a trolley. But doing the right thing is not always easy.

[5] We can test this idea by altering the story slightly. Suppose you， as the onlooker， could cause the large man standing next to you to fall onto the track without pushing him; imagine he is standing on a trap door that you could open by turning a steering wheel. No pushing， same result. Would that make it the right thing to do? Or is it still morally worse than for you， as the trolley driver， to turn onto the side track?

It is not easy to explain the moral difference between these cases—why turning the trolley seems right， but pushing the man off the bridge seems wrong. But notice the pressure we feel to reason our way to a convincing distinction between them—and if we cannot， to reconsider our judgment about the right thing to do in each case. We sometimes think of moral reasoning as a way of persuading other people. But it is also a way of sorting out our own moral convictions， of figuring out what we believe and why.

[6] Some moral dilemmas arise from conflicting moral principles. For example， one principle that comes into play in the trolley story says we should save as many lives as possible， but another says it is wrong to kill an innocent person， even for a good cause. Confronted with a situation in which saving a number of lives depends on killing an innocent person， we face a moral quandary. We must try to figure out which principle has greater weight， or is more appropriate under the circumstances.

Other moral dilemmas arise because we are uncertain how events will unfold. Hypothetical examples such as the trolley story remove the uncertainty that hangs over the choices we confront in real life. They assume we know for sure how many will die if we don’t turn—or don’t push. This makes such stories imperfect guides to action. But it also makes them useful devices for moral analysis. By setting aside contingencies—“What if the workers noticed the trolley and jumped aside in time?”—hypothetical examples help us to isolate the moral principles at stake and examine their force.

失控的電車

[1] 假設(shè)你是一輛有軌電車的司機(jī)，電車以每小時60英里的速度沿著軌道疾馳而下。在前方，你看見五個工人手持工具站在軌道上。你試著停下來，可是你不能，剎車失靈了。你感到無比絕望，因?yàn)槟阒?，如果你沖向這五個工人的話，他們將全部被撞死。（我們先假定你是知道這一點(diǎn)的。）

突然，你注意到右邊有一條岔道，那條軌道上也有一個工人，不過只有一個。你意識到，你可以將有軌電車拐向那條岔道，撞死這個工人，而挽救那五個工人。

你應(yīng)該怎么做呢？大多數(shù)人會說：“拐!盡管撞死一個無辜的人是一個悲劇，可撞死五個人將會更糟糕?！睜奚粋€人的生命以挽救五個人的生命，這看起來確實(shí)是正當(dāng)?shù)氖虑椤?/p>

[2] 現(xiàn)在讓我們來考慮另外一種與有軌電車有關(guān)的假設(shè)。這一次，你不是司機(jī)，而是一個旁觀者，站在橋上俯視著軌道。（這次旁邊沒有岔道）軌道的那一頭開來了一輛電車，而在軌道的這一頭則有五個工人。剎車又一次失靈了，電車即將沖向那五個工人。你感到自己沒有能力去避免這場災(zāi)難——可是突然你發(fā)現(xiàn)，你身旁站著一個身材魁梧的人。你可以將他推下橋，落入軌道，從而擋住疾馳而來的電車。他可能會被撞死，但是那五個工人卻將獲救。（你考慮過自己跳下軌道，可你意識到自己太小了，無法擋住電車。）

將那個魁梧大漢推落到軌道上是否為正當(dāng)之舉呢？大多數(shù)人會說：“當(dāng)然不是!將那個人推向軌道是極其嚴(yán)重的錯誤?！?/p>

將某個人推下橋致死看起來確實(shí)是一樁可怕的事情，即使這樣做挽救了五個無辜的生命。然而這便產(chǎn)生了一個道德難題：為什么這一原則——犧牲一個生命以挽救五個生命——在第一種情況下看起來是正確的，而在第二種情況下看起來是錯誤的呢？

[3] 如果像我們對第一種情形的反應(yīng)所暗示出的：數(shù)目很重要——如果挽救五個生命比挽救一個生命更好——那么，為什么我們不能將這一原則應(yīng)用到第二種情形，去推那個人呢？即使有一個很好的理由，將一個人推向死亡看起來也非常殘忍。然而，用一輛有軌電車撞死一個人就不那么殘忍嗎？

將橋上的那個人推下去之所以不對，可能是因?yàn)檫@樣做違背了他的意愿而利用了他。畢竟他并沒有選擇參與其中，他只是站在那里。

然而，我們可以對那個在岔道上工作的人說同樣的話。他也沒有選擇要參與其中，他只是在做自己的工作，在這失控電車事件中他并不自愿犧牲自己的生命。人們可能會辯解說，鐵路工人甘愿冒這樣的危險而旁觀者則未必會如此。然而，讓我們在這里假設(shè)，在緊急情況下犧牲自己以挽救他人的生命并不在這份工作的職責(zé)范圍之內(nèi)；并且這個工人與橋上的那個旁觀者一樣，都不愿意放棄自己的生命。

[4] 也許這里的道德差別并不在于對受害者的影響——他們都會死亡，而在于作決定的那個人的意圖。作為電車司機(jī)，你可能會這樣為自己將電車拐向岔道而辯解：盡管你可以預(yù)見到在岔道上那個工人的死亡，但是你并沒有想要他死。如果運(yùn)氣足夠好的話，那五個工人可以幸免于難而這第六個人也能存活，這樣，你的目的仍然能夠達(dá)到。

然而，這一點(diǎn)在推人落橋這一情形中仍然成立。你從橋上推下去的那個人的死亡，對你的目的而言并非不可或缺。他所要做的就是擋住電車，如果他能夠既擋住電車而又存活下來的話，你將會非常高興。

經(jīng)考慮，這兩種情形還有可能應(yīng)當(dāng)由同一原則來裁定。它們都涉及要故意選擇犧牲一個無辜者的生命，以防止一個更嚴(yán)重的損失。你可能僅僅是因?yàn)槟懶〈嗳酢环N你應(yīng)當(dāng)克服的猶豫——而不情愿將那個人推落橋下。用自己的雙手將一個人推向死亡看起來確實(shí)比轉(zhuǎn)動電車的方向盤更加殘忍，然而，做正當(dāng)?shù)氖虑椴⒉豢偸禽p而易舉。

[5] 我們可以對這個假設(shè)稍作調(diào)整以檢驗(yàn)一下這一觀念。假設(shè)作為旁觀者的你，可以不伸手推就能使身旁的大個子掉進(jìn)軌道；假設(shè)他正站在一個活板門上，你可以通過一個方向盤而打開這個活板門。不伸手推，便有同樣的結(jié)果。這是否使得這成為正當(dāng)之舉呢？或者，這是否仍然在道德上比作為有軌電車司機(jī)的你，拐向岔道更為惡劣呢？

要解釋這些情形的道德差別并非易事——為什么使電車拐向岔道似乎是對的，而將人從橋上推下就是錯的呢？不過，請注意我們在推理出兩者之間令人信服的區(qū)別時所遇到的壓力——如果我們推理不出來，那么就要重新考慮我們在每一種情形中對何謂正當(dāng)之舉所做出的判斷。我們有時候?qū)⒌赖峦评砜醋鍪钦f服他人的一種途徑，然而，它同時也是一種弄清我們自身道德信念，弄明白相信什么以及為何如此的途徑。

[6] 某些道德困境源于相互沖突的道德原則。例如，一種在脫軌電車故事中起作用的原則認(rèn)為，我們應(yīng)當(dāng)盡可能多地挽救生命；而另一種原則則認(rèn)為，即使有一個很好的理由，殺害一個無辜的人也是不對的。當(dāng)我們面對一種情形——其中我們要挽救一些人的生命就必須殺害一個無辜的人——的時候，我們便遇到了一種道德困境。我們必須弄明白哪一種原則更有說服力，或者更適用于這種情形。

另一些道德困境則源于我們不確定事情將如何展開。像脫軌電車這樣的假設(shè)的故事，排除了我們在現(xiàn)實(shí)生活中所遇到的選擇的不確定性。它們假定我們確切地知道，如果我們不調(diào)轉(zhuǎn)電車的方向盤，或不把那個大個子推下橋的話，有多少人會死去。這使得這類故事不能完美地指導(dǎo)現(xiàn)實(shí)行為，不過這也使得這些故事成為對道德分析有用的方法。通過懸置偶然性——例如，“如果那些工人看到了那輛脫軌電車并及時地跳開了呢？”那些假想的案例有助于我們孤立那些瀕于險境的道德原則，并檢驗(yàn)它們的力量。?