Throughout the history of mankind, three little words have sent poets to the blank page,
在人类的历史长河中，短短的三个字曾使诗人翻开新的篇章，
philosophers to the Agora, and seekers to the oracles: 'Who am I?'
使哲学家聚众讨论，使有信仰的探索者去寻求神谕：这三个字就是：“我是谁？”
From the ancient Greek aphorism inscribed on the Temple of Apollo, 'Know thyself,'
从刻在阿波罗神庙的古希腊警句：“了解你自己”
to The Who's rock anthem, 'Who Are You?'
到现代摇滚乐队The Who的摇滚名曲“你是谁？”
philosophers, psychologists, academics, scientists, artists, theologians and politicians have all tackled the subject of identity.
哲学家、心理学家、学者、科学家、艺术家、神学家、政治家都曾为这个有关身份的问题绞尽脑汁。
Their hypotheses are widely varied and lack significant consensus.
他们的猜想差异很大，而且在要点上缺乏共识。
These are smart, creative people, so what's so hard about coming up with the right answer?
这些可都是些聪慧绝伦，思维天马行空之人，得到一个正确的答案怎么会这么难呢？
One challenge certainly lies with the complex concept of the persistence of identity.
这其中一个很大的挑战就在于身份一致性这个观念的复杂特质。
Which you is who? The person you are today? Five years ago? Who you'll be in 50 years?
哪个你才是“我是谁”这个问题中真正讨论的“谁”？是今天的你？五年前的你？亦或是五十年后的你？
And when is 'am'? This week? Today? This hour? This second?
而“我是谁”中的“是”又说的是什么时间段的“是”呢？是指这一周？今天？这一个小时？还是说只有眼前这一秒？
And which aspect of you is 'I'? Are you your physical body?
还有，你的哪一个部分才是真正的“你”呢？你的肉体？
Your thoughts and feelings? Your actions?
你的思想和情感？还是你做出的实际行动？
These murky waters of abstract logic are tricky to navigate,
这些抽象逻辑的浑水很难驾驭，
and so it's probably fitting that to demonstrate the complexity, the Greek historian Plutarch used the story of a ship.
因此，希腊历史学家普鲁塔克用船的故事来说明这种复杂性，也许是恰当的。
How are you 'I'?
你为什么是“我”？
As the tale goes, Theseus, the mythical founder King of Athens,
故事是这样的，传说中创立了雅典的雅典王，忒修斯，
single-handedly slayed the evil Minotaur at Crete, then returned home on a ship.
在克里特岛单枪匹马杀死了邪恶的弥诺陶洛斯，然后乘船船而归。
To honor this heroic feat,
为了纪念这一壮举，
for 1000 years Athenians painstakingly maintained his ship in the harbor, and annually reenacted his voyage.
雅典人一千年来不辞辛苦地在港口维护着他的船，然后每年都用他的船重新完成他的航行。
Whenever a part of the ship was worn or damaged,
只要船的一个部分出现磨损或损坏，
it was replaced with an identical piece of the same material until, at some point, no original parts remained.
雅典人就会用一样的材料做出一块相同的来把它替换下来，到最后，船上没有一块是原来的部分了。
Plutarch noted the Ship of Theseus was an example of the philosophical paradox revolving around the persistence of identity.
普鲁塔克认为，忒特斯的这艘船，就是一个哲学悖论的范例，它体现了身份一致性这个难题。
How can every single part of something be replaced, yet it still remains the same thing?
如果一件东西的每个部分都被替换了，它怎么还会是同一件东西呢？

Let's imagine there are two ships:
让我们想象一下有这么两艘船：
the ship that Theseus docked in Athens, Ship A, and the ship sailed by the Athenians 1000 years later, Ship B.
船A是忒勒斯停泊在雅典的那艘，船B则是一千年后由雅典人航行的那艘。
Very simply, our question is this: does A equal B?
那么很简单，我们的问题就是，船A等于船B吗？
Some would say that for 1000 years there has been only one Ship of Theseus,
有的人会说，一千年来，忒勒斯的船只有这一艘，
and because the changes made to it happened gradually, it never at any point in time stopped being the legendary ship.
而且对它做的改造是逐渐进行的，在任何一个时间点，他都是那艘传奇式的船。
Though they have absolutely no parts in common,
即使船A与船B已经完全没有相同的部分，
the two ships are numerically identical, meaning one and the same, so A equals B.
但他们具有数目的同一性，也就是说，它们是唯一且一样的，所以，船A等于船B。
However, others could argue that Theseus never set foot on Ship B,
然而，另外一些人则会说，忒勒斯可从来没在船B上待过，
and his presence on the ship is an essential qualitative property of the Ship of Theseus.
而恰恰是他在某一艘船上待过，才使得那一艘船弥足珍贵。
It cannot survive without him.
如果没有他，那这艘船就不存在。
So, though the two ships are numerically identical, they are not qualitatively identical. Thus, A does not equal B.
所以，即使两艘船具有数目的同一性，它们却不具有性质上的同一性。所以，船A不等于船B。
But what happens when we consider this twist?
但是当我们考虑这个转折时会发生什么？
What if, as each piece of the original ship was cast off,
如果，每当船上一块旧的部分被替换下来，
somebody collected them all, and rebuilt the entire original ship?
都有一个人把它们全部收集起来，然后重新用它们造出原来的那艘船呢？
When it was finished, undeniably two physical ships would exist:
当这艘船完工的时候，毫无疑问，将存在两艘实体的船：
the one that's docked in Athens, and the one in some guy's backyard.
一艘停泊在雅典的海岸，另一艘在某个家伙的后院。
Each could lay claim to the title, 'The Ship of Theseus,' but only would could actually be the real thing.
两艘船都可以号称：“忒勒斯的船”，但只有一艘可以是真正的那艘。
So which one is it, and more importantly, what does this have to do with you?
那么那一艘才是呢，而且更重要的是，这跟你自己有什么关系呢？
Like the Ship of Theseus, you are a collection of constantly changing parts:
你，就像忒勒斯的船，是由一些不断变化的部分组成的：
your physical body, mind, emotions, circumstances, and even your quirks,
你的肉体、心灵、情感、身体状况，甚至是你的怪癖，
always changing, but still in an amazing and sometimes illogical way, you stay the same, too.
它们时刻在变化，然而在某种令人诧异且不符合逻辑的的程度上，你也还是一样的你。
This is one of the reasons that the question, 'Who am I?' is so complex.
这就是为什么“我是谁”这个问题如此复杂的原因之一。
And in order to answer it, like so many great minds before you,
可是为了回答它，你必须像那些古圣先贤一样，
you must be willing to dive into the bottomless ocean of philosophical paradox.
愿意潜入深不可测的哲学悖论的海洋。
Or maybe you could just answer, 'I am a legendary hero sailing a powerful ship on an epic journey.'
或者，也许你只需要回答：“我是一个传奇式的英雄，在伟大的航行中驾驶着一艘伟大的船。”
That could work, too.
这也算是一个答案。