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

翻译人员: Ying Lu 校对人员: Lipeng Chen

You’ve discovered a doorway to another realm,

你发现了通往另一世界的入口，

and now you and your brother

现在你和你的兄弟 准备出发来探索

are off exploring the wonderful world of Paradoxica.

“悖论”这个奇妙的新世界。

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

令人难以置信的神奇生物 在你四周爬行，奔跑和飞翔。

And then you see the troll.

接着你就看到了洞穴巨怪。

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

他正把所有的生物 抓入一个巨网中。

You bravely step forward and demand it let them go.

你勇敢地站了出来， 命令他将它们放生。

The troll laughs.

巨怪大笑道：“如果你是个 悖论的粉丝，

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

“then I’ll make you an offer.

那我给你一个机会， 如果你说了真话，

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

我将放走这些生物。”

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

就在你准备开口： “你是一个洞穴巨怪。”

but before you can, the troll grabs your brother.

说时迟那时快， 巨怪抓走了你的兄弟。

“If you say something false,” he continues,

“如果你说了假话，”他接着说道， “那我就放你的兄弟，

“then I’ll release your brother."

Your statement can only be a single sentence.

你的陈述只能是一个简单句。

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

正如你所见，我最讨厌悖论了。

If you try to cheat by saying something paradoxical,

如果你想靠说一些 模棱两可的话来作弊的话，

like, ‘this statement is false,’

比如，‘这句话是错的，’

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

那我不仅会吃掉你的兄弟， 还有这些生物。”

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

你能说什么是/非同时成立的 陈述来强迫巨怪

to free your brother and the paradoxical creatures?

不仅放了你的兄弟， 还放了那些神奇的生物？

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

如果你想要自己弄明白， 请暂停此视频！

Answer in: 3

答案揭晓：3

Answer in: 2

2

Answer in: 1

1

This seems like an impossible situation,

这看上去是一个无解的困境， 但令人诧异地是，你的陈述

but incredibly, you can say something

that will force the troll to release all its prisoners.

可以强迫巨怪放生 所有被囚禁的生物。

This is an example of coercive logic,

这是伟大的逻辑学家和谜语创作者 雷蒙德 · 斯穆里安提出了

invented by the great logician and puzzle creator Raymond Smullyan.

一个强制逻辑的例子。

The trick Smullyan came up with involves saying a statement

斯穆里安想出来的解决方式是

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

说一句真假与否取决于

你想让巨怪怎么做的话。

Your statement still has to be carefully crafted.

你说的话当然还得精心设计。

For example, if you were to say,

比方说，如果你想说：

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

“你会释放生物和我的兄弟，”

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

巨怪可以回答， “不对，我只会放走你的兄弟。”

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

同理，如果你说，“你将释放生物，” 巨怪可以回答，

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

“正确。”然后释放神奇的生物们。

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

但如果你说，

“你将放走我的兄弟。” 会发生什么呢？

The statement can’t be false,

这句话不可能是假的，

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

因为如果它是假的， 巨怪就得遵照他设定的原则，

would have to free your brother.

放走你的兄弟。

That would make the statement paradoxically true and false.

那这句话即为一个 既正确又错误的悖论。

But the troll hates paradoxes

但是巨怪讨厌悖论，

and would never willingly create one.

永远也不会自己想出一个。

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

所以他惟一的选择就是 承认这句话是正确的。

If “you will free my brother” is true,

如果“你将放走我的兄弟”正确的，

then the troll has to release your brother.

那巨怪就应该放走你的兄弟。

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

并且根据他自己的规则， 巨怪也必须放走那些生物，

since you said a true statement.

因为你说的是真命题。

By wielding just 5 words like a logical scalpel,

简单 5 个单词正如 一把逻辑的手术刀，

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

你成功让巨怪放走了他所有的俘虏。

As the troll stomps off in anger,

当你把巨怪气得跳脚时，

the paradoxes cheer you for winning them their freedom,

神奇生物正为 你帮他们赢得自由而喝彩，

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

并承诺将你带到台阶的 最高层寻找宝藏。

If you can reach it.

如果你能达到的话。