Thursday, 16 January 2014

The Ship of Theseus

This seems appropriate to post in honour of the actor, Roger Lloyd-Pack, who passed away today. Not only gave us the unforgettable Trigger, but also Owen in The Vicar of Dibley. And for Potter fans, Barty Crouch Sr. He was one of those great character actors who inhabited the roles he played that generally go unsung compared to often, less talented stars.

To anyone who doesn't remember it, there's a moment in Only Fools and Horses where Trigger gets an award for keeping his broom for 20 years. Then remarks that it's had 17 new heads and 14 new handles. It's funny because of course, what seems like a great achievement isn't really.

But there's a philosophical question in this too, that was originally asked long ago by Plutarch when referring to replacing all the timbers on the Ship of Theseus: if you replace all the timbers on a ship over time (or the head and handle on a broom), is it still the same ship?


Kj said...

I was thinking about something similar recently, an economics angle. I know someone who rebuilds vintage cars. The operation is getting a beat down skeleton of the car in question, and actually building everything around the chassis, including getting new plates shaped by workshops. And these cars are actually sold at a reasonably high price, although not as high as where all the parts are original ofcourse. So we can assume that the vintage factor is a separate premium, and the high labour costs of rebuilds another one. So the economic answer if we value the physical remnants of the original, is no. But OTOH, someone is also willing to pay a higher price for someone to rebuild something that has exactly the same qualities of the original, even if the practical utility is not worth it, so from that perspective, yes.

If an object has a shape, purpose, qualities at production, that you maintain by replacing the separate parts, maybe even all, it´s the same by fulfilling the same idea. It´s organizations vs. the constituent members.

Mark Wadsworth said...

It's a good philosphical question and nobody knows the answer.

These vintage car people definitely put a premium on "original" even if the replacement part (steel panel) is physically and chemically identical (I have no idea why).

And there are things where every single part is replaced over time - i.e. companies, orchestras, football teams, political parties and The Sugababes.

JimS said...

Wandering off topic but it has always puzzled me the way sports commentators come out with statements like, "it's been ten years since City won the cup", when everyone involved, management, players and opponents are most likely different. Looking for patterns where none exist?

Dinero said...

Interesting questions

JimS -you won't be very popular with football fans if you point out that nothing of the team is intrinsiclly the same over time except the ground.

Mark - I agree , its the same on property restoration shows when they knock down almost every wall of an old building with no roof and then start "restoring it". I always think for goodness sake stop fussing over those last bits and start from scratch.

Mark Wadsworth said...

Din, and sometimes football clubs move grounds, even if they stay in one place, stands get demolished and rebuilt etc, the turf gets replaced, new grass grows.

The Stigler said...


I find all those worlds like vintage cars, vintage toys, rare art and rare records odd now. I've never really figured out some of the rules that apply and why they do.

e.g. If someone discovers a possible lost Van Gogh or Monet, the talk is always about how if its the genuine article then it's worth more than not. But the purpose of a piece of art is its aesthetic value and whether it's by Vincent Van Gogh or Dick Van Dyke, the painting is the same.

Robin Smith said...

MW There is a definite answer.

Its discovered by what you make of the question.

If you treat the question literally, with the same kind of rigid logic, reason and rationality our campaign treats people in general, the response will be denial, paradox and psychological defences of all kinds. And reality is unable to determine the reality of the broom. This is observed, repeatedly, in fact. Infinite evidence is required forever to deal with it.

But if we treat it in metaphor, myth or symbol, everything falls into place, and it certainly is the same broom, where it matters most.

Can you see the real beauty in the character of Trigger now? Helping people transcend difficult realities, where infinite evidence fails, repeatedly, everywhere.

I know a German guy call Heinz Stucke. he got on his bike in 1962 and started cycling. He has still to get back home, been around the world 5 times.

His bike has been welded back together so many times with new tubes, the question arises:

"Is it the same bike?"

To Heinz there is no doubt about the answer. To those who take the question too literally, there is only denial, paradox and bitter and spiteful defence.

Derek said...

There are two answers to choose from. You can follow Plato and say that the form is the important thing and that the ship remains the same even if every timber is replaced or you can follow Democritus and say that the material is the important thing and that the ship is only original to the extent that it contains the original atoms.

Up to you which you choose really. It doesn't matter much unless you want to use the ship as a status symbol. In which case the atomic viewpoint is the best since you could in principle use the Platonic view to cut the ship in half and then restore each half, thus ending up with two Ships of Theseus. Under the atomic view, the two would only half be Ships of Theseus.

Anonymous said...

I wondered about the same question regarding Trigger's broom or Plutarch and the ship, when posed about teleportation of humans.[beam me up Scotty]. Even if you reproduced every single atom in the precise position as in the original traveler, the original would in effect be destroyed and a new copy made, albeit with the original set of memories and personality etc. Not the original traveler though...I think.

The Stigler said...


All organisations are basically about the people. OK, an organisation may have other things like brands and rights, but how long is a brand going to last if you're a bit crap?

I always say that the board of a company and their effect is hugely underrated. People say that it's down to the staff, but who hires and fires the staff, ultimately? Who sets the culture of the place? Who decides to buy which companies?

The Stigler said...


If someone teleports themselves having committed a murder, are they still guilty of it?

Derek said...

And yet, Paul, each one of us is made up of completely different atoms today than we were ten years ago. Sure there may be a few holdovers in some tissues. But fundamentally we are even more different from what we were ten years ago than if we'd gone through a Star Trek transporter

Derek said...

As a followup, here's a nice little article from the New York Times archives on how fast the various bits of the body get replaced. The researcher used a nifty trick based on the atom bomb tests of the 1950s and 60s.

Mark Wadsworth said...

D, re the two half ships, I suppose it only counts if you throw away the original parts and replace them.

So if I had been following Heinz around the world, collecting the discarded bits of his bike and I re-assembled them, that would NOT count as Heinz' actual bike.

My re-assembled bike might well have its own novelty or scarcity value, but I could not sell it as Heinz' actual bike on which he went round the world 5 times, because each of the individual bits might have only gone half way round.

Anonymous said...

TS. Well, if there were fingerprint or DNA evidence neither would change so I think there'd be a reasonable chance of a conviction. They'd still remember the murder etc and would feel as if they had committed it, so...

Derek, yes but we still consider ourselves the same person, due to us possessing the same memories.As the Trekkie would I suppose. It's only the brain that really counts isn't it. I mean, if you had a whole body transplant but kept your original brain [ala Robocop] you'd still consider yourself the same person at core, albeit visibly different. If you had a brain transplant though, you'd cease to exist and be whoever that brain used to belong to and that brain would consider its new body visibly different. Yuk.

Bayard said...

D, apparently the rules are:

In antiques, at least 50% must be original material, so it is theoretically possible to take one original Chippendale chair and make two original Chippendale chairs from it.

With ships, at least one peice of timber must remain from the original ship, hence when Joshua Slocum (of sailing round the world fame) rebuilt the boat that he did it in, the Spray, it was still the same Spray as he re-used the stem post.

With cars, I don't know. I do know that Parry Thomas's car, Babs is effectively a replica, incorporating only one part from the original car (which had spent decades buried under sand regularly inundated by the sea), but is still to be the original car in which Parry Thomas died.

Derek said...

Mark: yep, I can see that building a replica bike from the discarded parts would cause issues. In a similar vein, what if I bought the original Ship of Theseus, took it to bits and used all the parts to build a wooden house with it -- a bit like using Lego. Would it still be the Ship of Theseus? After a few years I could change my mind, take the house apart and rebuild the Ship of Theseus. Or could I?

Paul: Agreed on the memories thing and the brain transplants. There's a whole more that can be said about partial brain transplants and neurons with radio communication but I'll restrain myself in the interests of space.

Bayard: There's rules? Wow. Wonder who decides them?

Mark In Mayenne said...

If all the people in a company have changed over the years, is it the same company?

CIngram said...

I wrote about this very thing a few years ago, including the bicycle perspective, and offered a form of resolution. With apologies to out host for the self-promotion.

Derek said...

And in related news, an Australian billionaire plans to rebuild the Titanic. Will he be re-using any original parts?

Mark Wadsworth said...

CI, if you say it was the same bike, it was the same bike.

Even weirder is, my first wife and I used to drive my granddad's VW Golf, back in the late 1980s.

Round about 2007 or 2008, we both, quite independently (having split up in the early 1990s) both bought a new car (it was my first car for 15 years) and we bought more or less identical VW Golfs, both ca. 1997 (only mine has electric windows and hers had wind-up, which I prefer).

Was that the all same car? In a way it was, wasn't it?

PS, I've still got mine, she got rid of hers a couple of years later, dunno why.

Kj said...

MW: maybe your experience comes down to nostalgia and the fact that VW Golf is a very good car IMO. I´ve used a 2001-version from time to time, and it´s one of my absolute favourites. And you get quite used to the feel of a car and want it back. I´m checking out new cars and I´m instinctively only looking at newer versions of my previous cars :)

Bayard said...

There's rules? Wow. Wonder who decides them?

As far as ships are concerned, I suppose it must be something to do with Lloyd's Register or its equivalent in other countries. With antiques, it's to do with what you can state as being an "genuine" antique without being done for "passing off".