Tuesday, July 8, 2014

The Food Processor of Theseus Paradox

My Cuisinart Prep 9 food processor is broken- yet again.



Something made of plastic that gets lots of use only lasts so long.  Since buying the Prep 9 in 2009, I have broken and replaced the food processor bowl three times!  I've also replaced the blade once, the top that latches onto the bowl once, and now I'm replacing the pusher assembly.

Not much of my original food processor remains.  The only pieces of the machine which have not broken and been replaced are the motor base and the tiny pusher.    



My Prep 9 is not going to be whipping up any home made falafel in this state.  Without the replacement parts, it's not really my food processor.

But... when Cuisinart ships me my replacement pusher assembly, and I put all the replacement parts together with the base... can I still say what's sitting on my counter is the Prep 9 food processor I bought back in 2009?  With all those replacement parts, is its identity still the same?

An ancient Greek philosopher asked a similar question.  Not having my bad luck with food processors, Plutarch used the Ship of Theseus to ask whether the identity of something replaced piece by piece, gradually over time, is still the same entity when all its parts have been replaced.

Although the Ship of Theseus is now a famous philosophical paradox, its origins come from mythology.  Here's the myth in brief:  

Theseus volunteers himself as Minotaur food, hoping to defeat the Minotaur, instead, and return to Athens a hero.  Being completely without a texting plan, Theseus promises his dad that, if he succeeds and survives, he'll hoist a white sail on the sea journey home to let dad know all is well.  Well, a lot of stuff happens, and even though he does survive, Theseus forgets to put up the white sail.  His dad takes one look at black sail on Theseus's ship and commits suicide.  Theseus feels pretty badly about that, so he leaves the ship that should have brought good news in the harbor as a permanent memorial to his dad.

But, just as plastic parts can be expected to break, leaving a wooden ship in the water as a permanent memorial is just asking for trouble.  Wood in water just doesn't last forever- it rots.  But Theseus, being a king and all, tells his subjects to keep that ship maintained.  That means every time a beam rots or a board warps, or anything breaks, it has to be replaced. 

The Ship of Theseus stayed in the harbor for a very, very, very long time.  At a certain point not a single piece of the original wood remained.  The entire ship had gradually, piece by piece, been entirely replaced.  

So, Greek philosopher Plutarch asked- after all that replacing, is Theseus's ship still Theseus's ship?

I think what makes the Ship of Theseus Paradox so interesting is that it gets down to the question of identity, and not just the identity of really old ships and broken-down food processors- it makes me think about my own identity.

Cells are dying off and being replaced in my body little by little, all the time, every single day.  The molecules in my thumb aren't the same molecules in the thumb with which I was born.  So where is the continuity?  What is it about my thumb now that connects it to the thumb I gnawed on as a baby?  Am I the same person now as I was when I was a little kid?  A teenager?  A newly wed?  Will I be the same person twenty years from now, twenty days from now, twenty minutes from now?

And a stickier question: if I look really closely at myself, where am I, what makes me, me?  If I was in an accident and lost a foot, I'd be me without a foot, but I'd still be me- right?  Which parts could I afford to lose and still be Heather?

Maybe my identity can't be found in the body, maybe I'm the continuity of my memories.  If I get knocked in the head and lose all my memories, am I no longer me?  To explore a more likely scenario, what happens to my identity when my memories begin to fade?  Just the other day my husband insisted we watched Forbidden Planet together.  I don't remember it, at all.  How many memories can slip away before I'm no longer me?  

The paradox of the Ship of Theseus is a big question mark asking who am I, and what makes me, me.  For the time being I don't have a definitive answer, but that's okay.  I seem to be in pretty good company with others who find the question worth asking, even without a satisfying resolution.

The Ship of Theseus keeps coming up in my reading this month.  To read a more in-depth and exciting account of the myth behind the ship, check out  The Wisdom of Myths by Luc Ferry.  For some interesting perspective on personal identity, personality continuity, and a great retelling of the paradox employing pop bands, check out  The Ego Trick by Julien Baggini.