On Ship of Theseus

Aldarion

Neoreactionary Monarchist
"The Ship of Theseus is a thought experiment about whether an object that has had all of its components replaced remains fundamentally the same object."

One solution is basing the identity on the fundamental components of the ship. In this solution, a ship that has had all of its components replaced is a completely new object. But a ship that has everything except its ribs replaced is still the old ship, because ribs are the most fundamental part of its structure. Similarly, a computer would become a new thing upon replacing its motherboard.

Second solution is basically a mathematical solution: object becomes a new object one >50% of its parts had been replaced.

Third solution is looking at the continuity of existence. This is one that human brain tends to lean towards: most important aspect is the perceptual continuity. Thus a ship that has its parts replaced one by one never receives a new existential identity despite eventually having all parts replaced. But a ship that is demolished and built with new parts would receive new identity and thus not be the same ship.

Personally, I lean towards the third solution, albeit with some aspects of the first.
 

Marduk

Well-known member
Moderator
Staff Member
Another detail that could be included here is the matter of parts themselves changing their status.
If even 90% of the ship gets changed, and then the ship proceeds to be used by Theseus, then 100% of the ship can be considered the ship of Theseus yet again, even if the previously omitted 10% gets switched out the next time.
 

ParadiseLost

Well-known member
Another detail that could be included here is the matter of parts themselves changing their status.
If even 90% of the ship gets changed, and then the ship proceeds to be used by Theseus, then 100% of the ship can be considered the ship of Theseus yet again, even if the previously omitted 10% gets switched out the next time.

That is the continuity of existence?
 

posh-goofiness

Well-known member
Personally, I think the Ship of Theseus problem is only a problem because people are inexact in with their language when it comes to defining the problem.

Option 1 applies when you refer to the concept of a ship.
Option 2 applies when you refer to the matter that make up the ship, in which case, the ship is always in flux because its constantly losing atoms.
Option 3 applies when refer to the label you apply to an object.

All are valid and correct answers to the problem and none of them contradict each other so long as you clearly define the problem rigorously.
 

ParadiseLost

Well-known member
Interesting thought:

Shortly after I left for university, my family's toaster broke. Same brand and model, same appearance. By the time I got back it had enough wear, scuff marks, and stains on it that I could not have recognized that it was a different toaster without being told.

Question: if my perception of the toaster is the same to such a degree that from my perspective in continuity it effectively is the same toaster, does that imply that objects that are completely replaced all at once could still be effectively the same under the ship of Theseus problem?

I guess in this case the problem format would be: if Theseus's crew got drunk and sunk his ship while Theseus was gone, and by the time he returned they replaced it with an indistinguishably similar ship, would that, in a sense, be the same ship if Theseus never discovered the change?

TLDR: If a replacement is indistinguishably similar, is object continuity effectively maintained in a meaningful sense?
 

posh-goofiness

Well-known member
Interesting thought:

Shortly after I left for university, my family's toaster broke. Same brand and model, same appearance. By the time I got back it had enough wear, scuff marks, and stains on it that I could not have recognized that it was a different toaster without being told.

Question: if my perception of the toaster is the same to such a degree that from my perspective in continuity it effectively is the same toaster, does that imply that objects that are completely replaced all at once could still be effectively the same under the ship of Theseus problem?

I guess in this case the problem format would be: if Theseus's crew got drunk and sunk his ship while Theseus was gone, and by the time he returned they replaced it with an indistinguishably similar ship, would that, in a sense, be the same ship if Theseus never discovered the change?

TLDR: If a replacement is indistinguishably similar, is object continuity effectively maintained in a meaningful sense?
Depends on how you define the problem.
Is it the same ship physically? No.
Is it still Theseus' ship? Yes.
"Object continuity" is too vague a term for this question. It still comes down to what sort of continuity you are discussing.
 

Cherico

Well-known member
You are replaced bit by bit over time; your cells are all replaced eventually. You are a walking, talking, thinking ship of Theseus. Are you still you after 20 years?
No my experiences would have turned me into a different person
 

posh-goofiness

Well-known member
No my experiences would have turned me into a different person
Only in the sense that the physical parts that make up your body are different. The information, however, that constitutes your sense of self hasn't changed. Unless you have an altered or degraded mental state people don't dissociate which means you can assume you are still "you" even if the electrochemical processes that make "you" up are run using different atoms.
 

ProfessorCurio

MadScientist
Should only some external perspectives matter or should there in terms of what an object experiences also be in whatever ways are relevant an internal perspective of continuity?
Does only a perfect or near perfect copy need to percieve continuity or does the original need to?
And is continuity as many whole copy transhumanists say indeed an illusion?
 

ProfessorCurio

MadScientist
You are replaced bit by bit over time; your cells are all replaced eventually. You are a walking, talking, thinking ship of Theseus. Are you still you after 20 years?

The personality may evolve and new memories may be gained, however there is a smoothness to this transition and it is built in the very realm of the mind on the foundation of all previous elements.
Is the mind not the sum of its parts all of which run together and yet on their own times and individually.
Does the death or change of a single neuron change so drastically without recourse or redundancy the pattern of one's nature or determine the existence of the brain's dynamic nature and it's overarching patterns?
The mind is that dynamic process whereby experience, architecture, and adaptation bound by the former meet in a constant process to effect change upon the smaller preexisting elements of the aforementioned architecture.
The mind is no monolith whereby continuity is a binary aspect, but rather like a churning river which flows and changes and may tolerate to a point and even naturalize forced change from external factors using its own processes where they are compatible.
 

Captain X

Well-known member
Osaul
The 1995 anime film of Ghost in the Shell posed this question, actually. Not only had the Major's entire body been replaced, but most of her brain had as well. It doesn't help either that at one point she's traveling on a ferry and happens to see another woman with the same body as hers as far as having an identity crisis.
 

BlackDragon98

Freikorps Kommandant
Banned - Politics
I believe the 3rd solution . . . partially.

the object would still have its original name but with an added identifier.

For example: the Great Wall after being repaired and refurbished by the Ming Dynasty becomes the Ming Dynasty Great Wall or the Ming Great Wall, rather than just the Great Wall.
 

What's the sitch?

Well-known member
Needs to be a continuity of existence and a sort of acclimation period or its just a new separate object.
Not really gonna argue how much can be shifted over at a given time/stage and how much "value" each part has, but there is definitely a certain point.

Also regarding the arguement about what happens when you take all the original Theseus parts and put them back together after they have cycled out. You have just created a "new boat" from old parts, that is all, its not the Theseus. You can call it Theseus JR, Theseus 2, Theseus Classic or whatever.
 
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