You happen to be standing next to a switch that will divert the trolley onto a second track.

你碰巧站在轉轍器旁邊，它可讓電車轉換到第二條軌道。

Here's the problem.

這裡便產生了一個問題。

That track has a worker on it, too, but just one.

那條軌道上同樣也有工人，但卻只有一個工人在那。

What do you do?

這時你會怎麼做？

Do you sacrifice one person to save five?

你會犧牲一人來拯救其他五人嗎？

This is the "trolley problem", a version of an ethical dilemma that philosopher Philippa Foot devised in 1967.

這就是所謂的電車難題，是一個由哲學家 Philippa Foot 在 1967 年所設計的其中一版的道德困境。

It's popular because it forces us to think about how to choose when there are no good choices.

它非常知名，因為它迫使我們思考如何在沒有好的選項時做出選擇。

Do we pick the action with the best outcome or stick to a moral code that prohibits causing someone's death?

我們會做出導致最佳結果的行動嗎，或者我們會堅持道德準則、禁止造成有人死亡？

In one survey, about 90% of respondents said that it's okay to flip the switch, letting one worker die to save five.

在一項調查中發現，約有 90% 的受訪者認為翻轉轉轍器、讓一名工人死亡、以換取另外五名工人的存活是可被接受的，

And other studies, including a virtual reality simulation of the dilemma, have found similar results.

此外其他研究，包含一個模擬道德兩難的虛擬實境，同樣也得到了類似的結果。

These judgments are consistent with the philosophical principle of utilitarianism, which argues that the morally correct decision is the one that maximizes [the] well-being for the greatest number of people.

這些判斷和效益主義的哲學原理一致，它表明了道德上的正確決定就是最大化最多人的幸福 。

The five lives outweigh one, even if achieving that outcome requires condemning someone to death.

所以五人的生命比一人更有價值，即使為了達到這個結果會導致有人死亡。

But people don't always take the utilitarian view, which we can see by changing the trolley problem a bit.

不過人們不是永遠都以效益主義的觀點來思考，這點我們可從變化後的電車難題中看出。

This time, you're standing on a bridge over the track as the runaway trolley approaches.

這次，你站在軌道上方的一座天橋，這台失控的電車即將經過這座天橋。

Now, there's no second track, but there is a very large man on the bridge next to you.

現在沒有第二條軌道，但有一個身形非常龐大的男人恰好站在你身旁。

If you push him over, his body will stop the trolley, saving the five workers, but he'll die.

如果你推他一把，他的身體將使電車停止，並拯救了那五名工人， 但這個男人便會死去。

To utilitarians, the decision is exactly the same: lose one life to save five.

對於效益主義者來說，這個決定和先前的完全相同，它們同樣都是犧牲一人、拯救五人。

But in this case, only about 10% of people say that it's okay to throw the man onto the tracks.

但在這個情況裡，大約只有 10% 的人認為把人丟到軌道上是可接受的。

Our instincts tell us that deliberately causing someone's death is different than allowing them to die as collateral damage.

直覺告訴了我們，故意造就某些人死亡與間接造成他們死亡是兩回事。

It just feels wrong for reasons that are hard to explain.

基於某些難以解釋的原因，這令人感到不對勁。

This intersection between ethics and psychology is what's so interesting about the trolley problem.

而倫理學與心理學的交集正是電車難題如此有趣之處。

The dilemma in its many variations reveal that what we think is right or wrong depends on factors other than a logical weighing of the pros and cons.

在眾多版本裡的困境，顯示了我們思考對與錯的依據除了邏輯上權衡它的利弊之外，還在於各種因素的考量。

For example, men are more likely than women to say it's okay to push the man over the bridge.

舉例來說，男人比女人更可能認為把人推落天橋是可接受的。

So are people who watch a comedy clip before doing the thought experiment.

同樣地，如果進行思想實驗前受試者觀看了喜劇短片，那他們也更容易做出類似的判斷。

And in one virtual reality study, people were more willing to sacrifice men than women.

在一個虛擬實境的研究中，人們更願意犧牲男人，而非女人 。

Researchers have studied the brain activity of people thinking through the classic and bridge versions.

研究人員已經在探討人類思考經典版本與天橋版本時的大腦活動。

Both scenarios activate areas of the brain involved in conscious decision-making and emotional responses.

這兩種情景都會刺激大腦中關於有意識的決策與情緒反應的區域。

But in the bridge version, the emotional response is much stronger.

但在天橋版本中，情緒反應會更加的強烈。

So is activity in an area of the brain associated with processing internal conflict.

還有大腦中與處理內在衝突有關的區域，活動同樣也較劇烈。

Why the difference?

為何它們有所不同？

One explanation is that pushing someone to their death feels more personal, activating an emotional aversion to killing another person.

其中一項解釋說明：把人推落致死讓人感覺是自己親自動手，

But we feel conflicted because we know it's still the logical choice.

這激發了一種對殺死他人的厭惡情感，但我們會感受到衝突是因我們知道，這還是一個邏輯上的選擇。

Trolleyology has been criticized by some philosophers and psychologists.

某些哲學家和心理學家批評了電車難題。

They argue that it doesn't reveal anything because its premise is so unrealistic that study participants don't take it seriously.

他們認為這並沒有揭露了任何事情，因為它的假設是多麼地不切實際以致於研究參與者沒有認真看待它 。

But new technology is making this kind of ethical analysis more important than ever.

但是新的科技技術讓這類型的道德分析變得更加重要。

For example, driverless cars may have to handle choices like causing a small accident to prevent a larger one.

舉例來說，無人駕駛汽車可能必須去處理一些選擇，像是造成一個較小的事故、以防止更大事故的發生。

Meanwhile, governments are researching autonomous military drones that could wind up making decisions of whether they'll risk civilian casualties to attack a high-value target.

與此同時，政府正在研究軍用無人機，它最終可能要做出某些決策，像是它是否會冒著民眾傷亡的風險、以達到攻擊高價值目標物的目的。

If we want these actions to be ethical, we have to decide, in advance, how to value human life and judge the greater good.

如果我們希望這些行動變得道德，我們必須事先決定如何評估人類生命的價值，並評斷出更大的利益。

So, researchers who study autonomous systems are collaborating with philosophers to address the complex problem of programming ethics into machines,

所以那些研究自動化系統的研究人員與哲學家共同合作， 來處理把倫理道德編程到機器上的複雜問題，

which goes to show that even hypothetical dilemmas can wind up on a collision course with the real world.

這顯示了即使是假定的兩難局面，也可以應用在真實世界的衝突過程裡。