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Throughout the history of mankind,

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three little words have sent poets[br]to the blank page,

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philosophers to the Agora,

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and seekers to the oracles:

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"Who am I?"

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From the ancient Greek aphorism[br]inscribed on the Temple of Apollo,

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"Know thyself,"

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to The Who's rock anthem, "Who Are You?"

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philosophers, psychologists, academics,

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scientists, artists,[br]theologians and politicians

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have all tackled the subject of identity.

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Their hypotheses are widely varied[br]and lack significant consensus.

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These are smart, creative people,

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so what's so hard about coming up[br]with the right answer?

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One challenge certainly lies

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with the complex concept [br]of the persistence of identity.

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Which you is who?

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The person you are today?

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Five years ago?

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Who you'll be in 50 years?

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And when is "am"?

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This week?

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Today?

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This hour?

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This second?

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And which aspect of you is "I"?

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Are you your physical body?

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Your thoughts and feelings?

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Your actions?

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These murky waters of abstract logic[br]are tricky to navigate,

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and so it's probably fitting[br]that to demonstrate the complexity,

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the Greek historian Plutarch[br]used the story of a ship.

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How are you "I"?

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As the tale goes, Theseus, the mythical[br]founder King of Athens,

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single-handedly slayed [br]the evil Minotaur at Crete,

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then returned home on a ship.

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To honor this heroic feat,

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for 1000 years Athenians painstakingly[br]maintained his ship in the harbor,

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and annually reenacted his voyage.

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Whenever a part of the ship[br]was worn or damaged,

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it was replaced with an identical piece[br]of the same material

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until, at some point, [br]no original parts remained.

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Plutarch noted the Ship of Theseus[br]

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was an example [br]of the philosophical paradox

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revolving around [br]the persistence of identity.

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How can every single part [br]of something be replaced,

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yet it still remains the same thing?

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Let's imagine there are two ships:

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the ship that Theseus [br]docked in Athens, Ship A,

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and the ship sailed by the Athenians[br]1000 years later, Ship B.

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Very simply, our question is this:[br]does A equal B?

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Some would say that for 1000 years[br]there has been only one Ship of Theseus,

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and because the changes made to it[br]happened gradually,

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it never at any point in time[br]stopped being the legendary ship.

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Though they have absolutely [br]no parts in common,

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the two ships are numerically identical,[br]meaning one and the same,

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so A equals B.

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However, others could argue[br]that Theseus never set foot on Ship B,

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and his presence on the ship[br]is an essential qualitative property

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of the Ship of Theseus.

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It cannot survive without him.

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So, though the two ships [br]are numerically identical,

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they are not qualitatively identical.

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Thus, A does not equal B.

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But what happens [br]when we consider this twist?

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What if, as each piece [br]of the original ship was cast off,

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somebody collected them all,[br]and rebuilt the entire original ship?

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When it was finished, undeniably[br]two physical ships would exist:

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the one that's docked in Athens,

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and the one in some guy's backyard.

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Each could lay claim to the title,[br]"The Ship of Theseus,"

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but only would could actually[br]be the real thing.

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So which one is it,

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and more importantly, [br]what does this have to do with you?

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Like the Ship of Theseus,

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you are a collection of constantly[br]changing parts:

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your physical body, mind, emotions,[br]circumstances, and even your quirks,

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always changing, but still in an amazing[br]and sometimes illogical way,

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you stay the same, too.

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This is one of the reasons that [br]the question, "Who am I?" is so complex.

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And in order to answer it,

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like so many great minds before you,

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you must be willing to dive into the[br]bottomless ocean of philosophical paradox.

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Or maybe you could just answer,

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"I am a legendary hero sailing [br]a powerful ship on an epic journey."

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That could work, too.