• Fri. Jun 2nd, 2023

What’s the ‘ship of Theseus’ thought experiment?


May 27, 2023

The legendary ship of Theseus raises a number of philosophical questions. Right here, we see a Nineteen Twenties illustration of an historical Greek Bireme that has two decks of oars. (Picture credit score: Pictorial Press Ltd / Alamy Inventory Photograph)

As soon as upon a time — a minimum of in accordance with the traditional Greek author Plutarch — the hero Theseus sailed from Athens, Greece, to the island of Crete, the place he slayed the half-man, half-bull Minotaur earlier than crusing again to rule Athens. 

The wood ship that Theseus sailed on, Plutarch imagined, should have grow to be a nationwide treasure, and he posed a thought experiment that has fascinated philosophers ever since: When you repaired Theseus’ ship plank by plank in order that no authentic planks remained, is it nonetheless the identical ship? 

“The individuals who’ve been crusing the ship will say, ‘Yeah, it is the identical ship! We have been crusing for years, and we simply maintain fixing it,'” stated Michael Rea, director of the Middle for Philosophy of Faith on the College of Notre Dame. 

“However you may think about a collector wanting to place the unique ship within the museum,” Rea advised Reside Science. “She goes and gathers up all the unique planks, rebuilds them and says, ‘I’ve received the ship of Theseus!’ So, the query is, which one is the ship?”

Associated: What’s Occam’s razor?

Variations of the ship of Theseus thought experiment pop up all over the place. In Marvel Studios’ “WandaVision,” Imaginative and prescient comes face-to-face with a replica self and should work out who’s the actual Imaginative and prescient. In “The Good Place,” Chidi Anagonye lives a whole lot of separate lives and should confront which, if any, represents his actual self. In different eras, individuals have requested if an ax nonetheless counts as George Washington’s ax if each the deal with and the ax head are changed. 

“It seems like only a dumb get together puzzle, proper?” Rea stated. “However you may be taught quite a bit by pondering via these puzzles actually fastidiously.”

The ship of Theseus thought experiment raises questions in regards to the materials composition of objects: Is the ship the sum of its planks, the sum of its crusing historical past or each without delay? Can objects made up of different objects even be stated to exist? 

To reply these questions, philosophers should cope with conundrums similar to whether or not two issues can occupy the identical place on the similar time, how components relate to a complete and the way to consider the character of time. 

“The Story of Theseus” reveals Theseus’ ship and his killing the minotaur on the middle of the labyrinth.  (Picture credit score: Photograph 12 / Alamy Inventory Photograph)

One reply, Rea stated, is to say that solely the planks are actual and the ship “is only a section.” Taken to its logical excessive, this reply, nihilism, implies that solely elementary particles exist; objects made up of a number of components are simply an phantasm. 

However maybe ships do exist; if that’s the case, perhaps they’re outlined by their components. In that case, Rea stated, “the museum curator is right.” If objects can survive half alternative — our cells, for instance, are continually dying and being changed — then perhaps the ship at sea is the actual ship.

Or perhaps there have been two ships all alongside, generally sharing the identical location. In that case, Rea stated, “The phrases ‘ship of Theseus’ had been ambiguous, and that is why now we’re all confused.”

If two objects may be in the identical place on the similar time, it opens up a complete new can of worms — space-time worms, to be actual. 

Maybe the ship of Theseus exists as many overlapping chunks of space-time: The ship within the second when the primary plank was changed, the ship because it was when Theseus walked the decks and the ship’s whole existence, from the rising bushes that grow to be its planks to its afterlife as a philosophical thought downside. 

Associated: The place does the idea of time journey come from?

All of those ships collectively may be stated to “perdure.” “If I perdure, I am this four-dimensionally prolonged factor,” Rea stated. “Folks began calling these space-time worms.” This view often goes hand-in-hand with the concept that the previous and the long run exist — a philosophical stance referred to as four-dimensionalism — in distinction to presentism, a principle of time through which solely the current second is actual. 

None of this philosophical groundwork, nonetheless, can definitively say which ship is the actual ship.

“I feel that it is extremely fascinating that we’ve got this query in any respect,” stated Anne Sauka, a thinker on the College of Latvia. The query itself assumes a specific ontology, or principle of being.

She advised Reside Science that the ship of Theseus puzzle makes essentially the most sense within the context of substance ontology, through which objects are the main target of philosophical curiosity. The choice is a course of ontology, which sees change as extra basically actual than objects. 

Seen that approach, the planks, the ships and Theseus himself will not be static issues however slightly processes which are all the time shifting. Attempting to say both ship for Theseus demonstrates an unwillingness to let both ship evolve into one thing new. “The query itself reveals that we’ve got an issue with change,” Sauka stated. 

The ship of Theseus will also be seen as a metaphor for the self: “If we modify, are we a distinct individual?” Sauka stated. In course of ontology, change is the place to begin. “Selfhood is one thing that solely occurs by advantage of change,” she stated. Demise “is simply the dissolving of that individual course of that was a steady course of for a time.”