Follow TV Tropes

Discussion Main / TheseusShipParadox

Go To

Jul 31st 2016 at 7:45:32 AM •••

So I was wondering about this with two different characters who were both body-swapped and memory-wiped... (don't mouse-over the "one" potholes to see what the works are unless you want spoilers - this is in parts 10-11 out of 12-13 in both of them).

One treats it more like reincarnation - particularly since time-travel is involved. The two characters knew each other before the first one died, and the second one was created from his corpse long after. They meet when the new version gets his memories back, so he's sitting next to himself, but he can't be in two places at once, so they have to decide which one gets to live, and which returns to death. It's clear everyone in the situation thinks of them as two separate characters.

One treats them as the same person. It helps that there's no time travel involved, and there's only one of him at a time. He's an immortal, incredibly powerful figure, memory-wiped and body swapped into an ordinary high school student. I was thinking about him and the way he acts early on, amazed at how he really thinks he's just an ordinary high school student... and then I thought of this paradox - one could say that at that moment, he is an ordinary high school student. Imagining if someone had told him his true/original identity before his memories returned. It would just freak him out. He wouldn't feel made-whole, he would feel broken. And when he gets his memories back, he tells his companions, "I may be (old name), but I'm still (new name). Nothing's really changed." It's not really clear which he sees himself as. He returns to his original body, and apparently he goes by his original name, but that could be because his original body is German and the body he was borrowing - and his new name - are Japanese...

... I guess I tend to take the Buddhist view on this - it is what it needs to be, the x of ten years, twenty years, etc. ago isn't the same as the x of today, but why does it need to be? Kinkakuji is Kinkakuji, and it's magnificent whether it's new or old. Though I doubt modernists would accept its claim to the term "new"...

But what do you think?

Edited by lavendermintrose
Aug 22nd 2014 at 1:15:58 PM •••

Earlier this month, hbi2k slapped this into the Real Life section of the article:

5th Aug '14 1:43:03 PM hbi2k
Changed line(s) 50 (click to see context) from:
* A popular urban legend has it that the human body replaces all of its cells (some say all of its atoms) every seven years. Averted: this is just that, an urban legend with no basis in fact. The body replenishes dead cells at different rates, and some cells (most notably the neurons in the brain) are never replaced if they die.

There are multiple problems with this claim—first among these, that hbi2k insists there is "no basis in fact" while simultaneously admitting that the body does replenish dead cells for much of its makeup.

This makes the urban legend a half-truth, not a complete fabrication—especially since, with respect to Real Life examples of this trope, there are multiple examples of objects which are debated to be examples of this paradox even when they still contain a significant amount of their original material (see the wooden-hulled ship examples—in fact, before I made my edits, the original example discussing the USS Constitution was right above his addition).

Because the Ship of Thesus Paradox is invoked and discussed with respect to real-life objects which haven't had all of their parts replaced, it stands to reason that the paradox could be invoked when discussing the human body if we recognize that yes, much of the human body does get replaced over time.

So, I modified his entry to be less problematic ...

21st Aug '14 3:58:21 AM Trev MUN
This is not an aversion. The body is still replacing old cells with new ones, so it plays the trope straight regardless of the urban legend.
Changed line(s) 50 (click to see context) to:
* A popular urban legend has it that the human body replaces all of its cells (in some versions, all of its atoms) every seven years. While not strictly true, it does have a basis in fact despite what some may tell you. With the exception of certain types of cells (such as neurons in the brain), cells of the human body continually die off and are replaced with new ones at different rates. Given enough time, most of the tissues in a person's body will not contain any of the cells from a previous point in their life.

... only for hbi2k to swoop right in four hours later and add his example back into the article (but not replace the original that I modified):

5th Aug '14 1:43:03 PM hbi2k
No, it IS an aversion, because there are some parts of the body that are never replaced, therefore there is an unbroken continuity between your physical self all through your life up to your death. This trope is about instances where ALL of an object's parts are replaced at one point or another.

I'm going to say it again, hbi2k: your example is not an aversion, especially with respect to how this paradox is used when discussing real life objects. TV Tropes did not invent the Ship of Thesus Paradox.

I did give you the benefit of the doubt when modifying your initial example by noting that only most of the human body is continually replacing dead cells with new ones, but I could challenge your claims about, say, the human brain being a static organ by reminding you what neuroscience has learned of neuroplasticity in recent decades.

Edited by Hide/Show Replies
Aug 22nd 2014 at 1:20:50 PM •••

It's an urban legend. If we list it as such then the part about aversions needs to go, since the real life factual accuracy is irrelevant then.

Aug 22nd 2014 at 1:25:21 PM •••

That would also be a good idea. It'd certainly avoid any further debate on whether or not it had a basis in fact or not.

Aug 22nd 2014 at 1:54:14 PM •••

I never said anything about the human brain being a static organ. I honestly have no clue where you got that from. I said there are parts of it that are there from the day you're born until the day you die, which should be fairly uncontroversial. It's not the bit about parts of your body replenishing themselves that has no basis in fact— that should be pretty self-evident to anyone who's ever had a haircut— but the supposed seven-year-cycle, which is an invention of popular imagination.

I must have missed the fact that you replaced my example rather than simply deleting it. I've commented out your version while we hash this out.

Stripping away the passive-aggressive language referencing my original version would render it something like this:

Urban Legends

  • A popular urban legend has it that the human body replaces all of its cells (in some versions, all of its atoms) every seven years. While cells of the human body continually die off and are replaced with new ones, they do so at different rates, and there are exceptions such as neurons in the brain and parts of the skeletal structure. The supposed "seven-year-cycle" is an invention of the popular imagination and has no basis in fact.

Is that acceptable to you?

Edited by
Aug 22nd 2014 at 2:03:13 PM •••

I think it's safe to just say "A popular (though untrue) urban legend..." and lop off the last sentence, as well as change "seven years" in the first to "every few years" because I've heard it as many different lengths of time.

Aug 22nd 2014 at 2:52:59 PM •••

I've heard it as a few different lengths of time, most commonly seven, sometimes ten. Part of the urban legend is that it's a fixed length of time, though, so some reference to that should stay in. Maybe:

  • A popular but baseless urban legend has it that the human body replaces all of its cells (in some versions, all of its atoms) at regular intervals, usually seven or ten years. While cells do continually die off and are replaced with new ones, they do so at different rates, with no regular cycle of years. There are also exceptions, such as neurons in the brain and parts of the skeletal structure, which last a lifetime and are not replenished.

Type the word in the image. This goes away if you get known.
If you can't read this one, hit reload for the page.
The next one might be easier to see.

How well does it match the trope?

Example of:


Media sources: