Ship of Theseus Paradox

[HighlyIrregular II]

Could someone mention Mashy if this doesn't work... @mashy

https://web.archive.org/web/20201128223 ... us-paradox

Ship of Theseus paradox
Theseus owns and sails a ship. Every month, when he sails to port, he has one old plank of his ship replaced with a brand new plank. By the time 10 years has passed, not a single original plank of wood remains in Theseus’ ship. Unbeknownst to Theseus, however, the ship repairman has saved all of the old planks that he removes from Theseus’ ship.

Slowly, he constructs a new ship. By the time 10 years has passed, he has acquired every single original plank from Theseus’ ship and arranged them exactly as they were in Theseus’ original ship.

Which of the two existing ships is numerically one and the same ship as Theseus’ original ship? Is it the ship with all new parts, or the re-constructed ship with all of the original parts?

Neither is number one. The one reconstructed from original planks should be qualified as such due to the entirely new fasteners and absence of the old ones and the fact that the ship never was sailed by the original sailor when it had the new fasteners. The one with different material also should be qualified as such. Things are disassembled, moved, and reassembled all the time, but when to call them original, unqualified, should be considered on a case by case basis.

[Senseye]

I'd still vote for the ship Theseus owns. And keep in mind Theseus replaced those planks for a reason. Weathered, cracked, barnacled, what have you. Some of those planks replaced in the later years were probably on their last legs.

The copy ship from recycled planks is probably pretty rickety. I wouldn't be surprised if the ship repairman didn't have to replace a few with other planks himself before he even set sail.

[Utisz]

Whichever answer fills your heart with joy.

[Senseye]

I've been watching the Tally Ho Youtube videos. I just kind of stumbled across them after seeing a news clip that the boat was recently launched. I find the videos surprisingly interesting considering I am not into either boats or woodworking at all.

Anyhow, this guy bought and old wooden yacht originally built in 1910 and rebuilt it over 6 years. It's basically a ship of Thesus. He does reference the paradox in his videos a few times as well. So far (I'm only about 30% of the way through the videos) he has had to replace everything. He does keep the old wood around though, and I think he is planning to recycle what he can when constructing the interior. Still it will be mostly a new boat, but it's built based on the original plans and the boat is never really deconstructed at any point, so it always seems like he is just fixing the original boat.