Can you solve the troll’s paradox riddle? - Dan Finkel

譯者: Ann Chen 審譯者: Helen Chang

You’ve discovered a doorway to another realm,

你發現一個 通往另一國度的出入口，

and now you and your brother

現在你和你的兄弟 出發前往奇妙的悖論世界探險。

are off exploring the wonderful world of Paradoxica.

Fantastically paradoxical creatures crawl, run, and fly around you.

奇異的悖論動物在你四周 爬行、奔跑和飛行。

And then you see the troll.

然後你看到巨人，

It’s catching all the creatures in an enormous net.

牠正用一個極大的網子 捕捉所有的動物。

You bravely step forward and demand it let them go.

你勇敢地走向前 要求牠釋放牠們。

The troll laughs.

巨人大笑，牠說： 「若你真是個悖論迷的話，

“If you’re such a fan of paradoxes,” it says,

“then I’ll make you an offer.

那麼我給你一個交換條件， 如果你說真話，

If you say something true, I’ll release all these creatures."

我就釋放所有動物。」 當你正要說：「你是個巨人。」

You’re about to say, “You are a troll,”

but before you can, the troll grabs your brother.

但話還沒出口， 巨人就抓起你的兄弟。

“If you say something false,” he continues,

牠又說：「如果你說假話， 那我會放你兄弟。

“then I’ll release your brother."

Your statement can only be a single sentence.

你的話只能是單一句子。

And as you can see, I hate paradoxes more than anything.

如你所見，我最討厭悖論。

If you try to cheat by saying something paradoxical,

假如你試圖 說些矛盾的話來蒙騙我，

like, ‘this statement is false,’

例如『這話是假的。』 那麼我會吃掉你兄弟和動物。」

then I'll eat your brother and the creatures."

What true/false statement can you say to force the troll

你能說出哪句真／假的話，

迫使巨人釋放你兄弟和悖論動物呢？

to free your brother and the paradoxical creatures?

[Pause the video now if you want to figure it out for yourself!]

假如你想自己解解看， 現在將影片暫停。

Answer in: 3

答案即將公佈：3

Answer in: 2

答案即將公佈：2

Answer in: 1

答案即將公佈：1

This seems like an impossible situation,

這似乎是個不可能的任務， 但很奇妙地，你是可以說個

but incredibly, you can say something

that will force the troll to release all its prisoners.

迫使巨人釋放所有囚犯的話。

This is an example of coercive logic,

這是個「強迫邏輯」的例子， 是由偉大的邏輯學家

invented by the great logician and puzzle creator Raymond Smullyan.

及益智遊戲創造家 雷德蒙·斯穆里安發明的。

The trick Smullyan came up with involves saying a statement

斯穆里安提出解謎的訣竅

whose truth or falseness depends on what you want the troll to do.

在於所用的句子是真或假

是依你希望巨人做什麼而定。

Your statement still has to be carefully crafted.

你仍須小心斟酌所說的話。

For example, if you were to say,

例如，假如你說：

“You are going to free the creatures and my brother,”

「你會放動物和我的兄弟。」

the troll could respond, “that’s false… I’m only going to free your brother.”

巨人可能回答： 「錯了…… 我只會放你兄弟。」

Similarly, if you said, “You will free the paradoxes,”

同樣地，若你說： 「你會放悖論動物。」

the troll could say, “That’s true,” and free the paradoxes.

巨人可能說：「那是真的。」 然後釋放悖論動物。

But watch what happens if you say, “You will free my brother.”

但注意以下會發生什麼事， 假如你說：「你會放我兄弟。」

The statement can’t be false,

這句話不可能是假的，

because if it were, the troll, by its own rules,

因為如果是假的， 根據牠自己的規則，

would have to free your brother.

牠就必須釋放你的兄弟。

That would make the statement paradoxically true and false.

那會使得那句話自相矛盾。

But the troll hates paradoxes

但巨人討厭悖論

and would never willingly create one.

且絕不願意去創造一個。

So his only option is for the statement to be true.

所以牠唯一的選擇 是把這句當真。

If “you will free my brother” is true,

假如「你會放我兄弟」是真的，

then the troll has to release your brother.

那麼巨人必須釋放你的兄弟。

And by its own rules, the troll has to free the creatures as well,

根據牠的規則 巨人也須釋放動物，

since you said a true statement.

因為你說了一句真話。

By wielding just 5 words like a logical scalpel,

僅用五個字， 如同用邏輯手術刀般，

you’ve forced the troll to free all its prisoners.

你已迫使巨人釋放所有囚犯。

As the troll stomps off in anger,

當巨人怒氣沖沖跺步離去，

the paradoxes cheer you for winning them their freedom,

悖論動物為你贏得牠們的自由喝彩，

and promise to lead you to the treasure at the top of the stairs.

而且答應帶你去拿樓梯頂端的寶藏，

If you can reach it.

只要你到得了的話。