Theseus' Ship - what's your opinion?

Here's something I read a while ago on the net. I find it fascinating.

This is the story:

Theseus is famous in Greek mythology as the slayer of the Minotaur, a half-man, half-bull monster who lived in the Labyrinth in the island of Crete. According to Plutarch, the ship in which Theseus sailed back to Athens was preserved for many generations, its old planks being replaced by new ones as they decayed.

Now suppose that a few hundred years later, all the original parts of the ship had been replaced, one by one, so that none of the original ship remained. Is the preserved ship still Theseus' ship? Or is it a copy? And if the latter, then at what point did it cease to be Theseus' ship?

This problem involves the notion of identity, of what we mean by something being the "same" object. Suppose that we regard the final ship as Theseus' ship. What if all the old planks, nails, etc., had been stored in a warehouse and someone put them back together again? Would there then be two Theseus' ships?

What's your opinion?

 

Interesting question, and it's too early in the morning for me to think up an opinion, but something just struck me:

Aren't the cells in our body supposed to die and be replaced on a regular basis? I heard that they all (save the brain cells and those that make up the central nervous system) get replaced every seven years.*

Considering which, we're in much the same position with our physical bodies. I'm not sure how relevant that is to your original question, but I thought I'd throw it in.


(* Disclaimer: I may be way off with this one - please correct me if I am!)

 

Of course it's not the same ship. Would you take off your clothes, put on different clothes and then say you wearing the same thing?

Technically it's Theseus' ship as long as it belongs to Theseus though.

 

Interesting point. However, when you cast off old clothes and put on new ones, you're not integrating the clothes into yourself (can't think of a better way of putting it).

So what about if you cast off old dead body cells and grew new ones, then after a few years you're no longer in your own body?

True, at that level. However, I interpreted it as "the ship that Theseus used to sail in" rather than "the ship that's owned by Theseus."

 

Interesting points, men.

About the body cells. . . I'm not positive, but I was under the impression neurons never replace themselves (new brain cells created in the cerebellum don't count). But I see what you're trying to say, CF. In terms of physiology, a better example may be the skin cells. They replace themselves at an alarmingly rapid rate: Every 15 to 30 days your body completely replaces the outermost layer of your skin. So in a month's time, you're litertally wearing a new birthday suit. Kinda cool, huh?

But - even this can be hard to relate with the analogy of Theseis' ship. The skin cells were yours to begin with, right? The replacing pieces were already part of your body. Replacement did ocurr, but there really wasn't a foreign body doing the job like there was with Theseus' ship. So it's harder to draw the line between one body (of matter) merging into the other.

Let's say a single wooden plank rots on the ship, and you replace it with a fresh wooden plank. Does the new plank immediately become one of the many parts that's defined as Theseus' ship? Or is it simply a foreign body latching on to the old? It's easy to say yes to both, isn't it?

That interpretation by itself could close the debate if not for the other. It's definitely an interesting way to look at it, though.

This whole thing makes me think of the movie Bicentennial Man, although I don't think the same rules apply. If you've seen the movie, I think you'll know what I'm talking about.

 

"This old broom's had 17 new heads and 14 new handles in its time." -Trigger

Only fools and horses can be so deep sometimes!

 

Ever heard the expression 'George Washington's axe'? It's the same idea. New head and new handle - but it's still George Washington's axe.

I hadn't heard about Theseus's ship though. Is it still part of the Greek navy?

 

So you're saying the analogy has gone too far in the other direction (from Ragnarok's clothes analogy)?

It's a damn good question isn't it, and really gets you thinking. Perhaps it's worth making a distinction between ownership and labelling. i.e. Theseus as the ship's owner, and the ship in itself which is identified as distinct from other ships by being labelled as Theseus' ship. But even then, in both cases, I can see the strongest argument pointing towards "yes, it is Theseus' ship".

Here's another thought: because it's subjective anyway, it depends on your perspective. If you want to see it as Theseus' ship then it is, and if you don't want to see it as Theseus' ship then it isn't.

Hmmm my brain hurts now.

Off topic: I've never seen that - is it worth renting?

 

oh such dastardly opportunity..

i think change and beginning is always occuring at all levels at some level..

every new plank is a begining of change. The 'last' plank is yet another begining. And the process begins its change again - always back to a begining.

it never was 'theseus ship' and never will be 'that ship' from the moment the first tree was chopped the wood was dying.. and so is everything..

But on that black note, there is always a flipside.. we calls it 'force'

nite nite.

zd

 

Whoa - I suddenly realized how important of a role ownership plays in this debate. And realizing this gave me a very in-your-face thought. Let's dig a little deeper. Just a little.

I think the story's lacking a very important detail. Unless the guy is a super-human Greek figure who lives 300+ years old, I think we can all agree that Theseus dies.

When, we don't know. By using common sense, I think we can assume he owned the ship when it was brand new. And, by using common sense again, we can assume new captains claim the ship and continue sailing it after Theseus dies. But, in my theory, who the captains are is irrelevant. The bottom line is, the ship ceased to be Theseus' after his death. The ship that gets put back together doesn't even matter in this theory.

Lack of detail makes accurate answers near impossible. Think about some of the things that are missing here: The story doesn't say who's maintaining the ship as it's rotting. We don't know if Theseus sold his ship before it started to rot. And by the way, who's in charge of storing the discarded ship pieces? Does that person own the rot that later becomes a ship again?

Your thoughts?

Johnno: I've no idea about the history of the story. Sorry.

zendog: That's pretty deep stuff and it sounds neat, but I think ownership plays a key role in the story (which defies what you're saying). The lumber company bought the land which held the trees which later became the ship that Theseus owns. *shrug* You can trace back forever, but in the end, I think it becomes Theseus' ship. But then again, everything I just said went against your post.

CF: The movie's definitely worth the rent.

*falls over*

 

owning a ship is a bit like owning a house. Ownership and identity are both transient.

the house you and your family live will no doubt outlast you. One day though it will crumble too unles it is well renovated - one day it may be like theseus's ship. all new - or it may be all gone.. perhaps to be recycled!

So with this in mind what really ever gets or stays owned..

It is all just in passing through - wood, bricks, money, ownership, identity..etc. keep it in the family !

Regards zd

 

In the example of the human cells, it's not a particularly good one, because a ship doesn't have a consciousness or a soul. A human is not defined by their body (well, unless you're shallow and materialistic), but by the person they are, and that is non-physical because is comes in the forms of throughs, emotions, and whatnot, which are all non-physical.

The ideas can be replaced, the emotions can change, but in the end, down at the core the person is still the same, they are just evolving. If we look at evolution, due to the unusual usage of the word, we see that when a species changes a certain amount it is renamed so that the different stages can be catalogued. These are not what it is though. A name is just a word, like love, it doesn't really change who we are because it is only an expression of who we are.

So is Thesues' Ship still Thesues' Ship? So long as we all know that the body that was once Thesues' Ship is that ship, then yes.

 

Hey, I agree it's an interesting question, and i'm possibly too tired to write a big response! But I wanted to comment on ur body cells replacing themselves.
You're quite right, but actually your whole body from bones to blood is replaced entirely within just 6 months!
And actually, if you wanna talk what's really here, the atoms that make up your cells (and everything else) actually disappear and reappear thousands of times a second. So really, other than wondering where the hell they go, you could argue that they're no longer the same as before, and you as a person have been changed.
Ho hum, yeah mite write more another time.

 

So you agree with the "there are two Theseus' ships" theory? Remember, the parts that are being replaced are stored in a warehouse then put back together to re-create Theseus' old ship.

 

Since an inorganic object cannot, to our knowledge, possess a consciousness, the name we give it has to suffice. Therefore as long as it retains the name "Theseus' Ship", if only during the course of this mental activity, it is still Thesues' Ship.

 

Sorry, no. Atoms don't "disappear and reappear". The laws of conservation of matter and energy prevent this sort of thing, which would otherwise prove quite inconvenient . What I think you meant was that the molecules making up your cells/body (eg. proteins, fats, etc.) are constantly changing. The atoms get shuttled along and converted from one molecule to another, but only excretion makes them "disappear" from your body.

On the larger question, I don't think personal ownership has anything to do with it. Nor, for that matter, does the amount of original and replacement materials at any particular time. What really matters here is public perception or collective consciousness. Items such as Theseus' ship or George Washington's axe take on a type of immortality based on how they are perceived by the population. As long as they are viewed in a certain way, they will ALWAYS be Theseus' ship and Washington's axe, regardless of material or current ownership. When they are forgotten, then they just become an old ship or a rusty axe.

This explains the phenomenon seen frequently in many Ebay-type auctions, where people are willing to pay massive amounts of money for something that is otherwise ordinary because of the fame of the item or it's owner. A great example of this is the car that went up for auction recently and sold for several times its material worth because it had been owned and driven by the Pope. It was still the Pope's car, even though he sold it years ago.

Just thought I'd throw the philosophical monkey wrench into the bathtub...

 

That makes sense; I see where you're coming from. You perceived the ship as "The ship that Theseus once sailed" and Washington's axe as "The axe that Washington once used" instead of in terms of ownership, as I did. And that's where I think there are conflicting truths.

Check out the excerpt from the story: “Is the preserved ship still Theseus' ship?” Following the rules of English, where the apostrophe is located indicates ownership of the object; if the sentence was structured differently in terms of no ownership, the sentence would probably say, “Is the preserved ship still the ship that Theseus [once] sailed?”

I know I know, it's being awfully technical. . . but I think I've got a point. What do you think?

 

wow, ambiguous answers aplenty. i'm gonna say 50%. it stops being his ship after 50% of it is replaced.

 

Why? Wouldn't 50% percent of the ship still be Theseus'?

 

This was addressed by the Buddha of our physical reality 2,500 years ago, which is basically empty in its core but formed by a myriad of ever changing phenomena conditioned by a cause-effect relationship. Hence the correct term that describes the transitoriness of all conditioned phenomena (you exist because you are the product of a male and female union during sexual intercourse, but which eventually will disappear with the physical death) is Anicca in Buddhist terminology.


DC.