The Ship of Theseus

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?

Theseus' ship is still ship number 1. It is refurbished, but it is still the original. The other is a salvaged vessel.

Marconius wrote:Theseus' ship is still ship number 1. It is refurbished, but it is still the original. The other is a salvaged vessel.

What makes ship 1 ship 1? What is it that is more than the sum of its parts?

It is the sum of Theseus' labor. If he wouldn't have done it plank by plank over a period of time, I may answer differently.

Look at it this way:

Is my '71 Mustang really a '71 Mustang just because many of the parts are new???

Marconius wrote:It is the sum of Theseus' labor. If he wouldn't have done it plank by plank over a period of time, I may answer differently.

Look at it this way:

Is my '71 Mustang really a '71 Mustang just because many of the parts are new???

Is it?

Interesting you should mention your Mustang as an example, I posted a variant of this on the Jeep Forum general discussion last week.

http://www.jeepforum.com/forum/f7/what-makes-jeep-1488980/

Are you purposefully trying to make my head hurt on a Monday morning