Ok so ive been trying to prove myself wrong here but I probably don't know enough about realmatic science and shardblades to do it. Please help me fellow nerds!
When a shardblade cuts a limb, it "kills" the limb from the cut point through the end (ex. Arm cut would kill the arm through the hand). But why does it not kill the other way instead (ex. Arm cut would kill from cut point through rest of body but the hand remains living)? Is there a reason for this?
This also spawned other questions like: What if someone cut vertically down someones torso all the way through their body without hitting the head or spine? Would they die? Do the brain/heart/spine have something special about them when it comes to the soul?
My crazy theory: My initial thought was because humans believe that when you cut off an arm with a real sword, it falls off and the body lives. And since perception plays such a large role in how investiture effects the world, shardblades operate that way when humans wield them. But if a human truly believed and perceived that if they cut off a finger, it would cause the bodily decay to go towards the rest of the body, would it work?
Cognition flows through nerves, from the brain. The shardblade stops the flow at the point of contact, severing the cognitive, like turning off a tap. Stormlight heals the point of severance allowing the cognitive power to flow again. Unless you have enough brains in your hand, it’s not going to work the other way.
Something that has enough neurons (like an octopus) in appendages / or generally decentralised, might work differently.
Pretty much correct except that the shard blade cuts the spiritual aspect, not the cognitive
But then we get to a Cartesian dilemma: Where is the soul geographically speaking? Does it come from the brain? If so, if you damage someone's brain you're damaging someone's soul? I guess it should be true since you can kill a radiant by cutting their spine, but it's still weird.
can you transplant a soul? can you transplant a brain? answer to both is no. (though maybe one day we can do the brain). but the brain contains your identity and thus would also contain your soul
>can you transplant a soul?
You can with hemalurgy
just what I thought. yet I don't think you could transfer a brain in the cosmere
A shardspike, hmm
"The art that is unique to Hemalurgy, however, is the knowledge of where to place the spikes."
In the cosmere, the soul is spread throughout the body
There's probably a purposeful interaction between how much of a person would be "killed" by passing a shardblade through whichever part and the way a person's spirit web is arrayed throughout their body. The same reason (general Mistborn spoilers) piercing different bits of the human body with hemalurgic spikes yields different results depending on the metal and the bit spiked.
Ooooo i love the hemalurgy relation! Cool connection!
I think it just follows the same rules of biology. Why when you cut off someone's arm in real life does it work one way and not the other?
Follow-up question.
Imagine an Ancient Egyptian High Priest, of Thoth or something. Truly 1000% believes and believes he knows that the brain is a useless hunk of gunk and that the heart is the seat of thought, reason, and logic. Chop him through the neck with a shardblade. Does he survive? (Albeit blind, deaf, unable to swallow, speak, or balance, and so on.)
Edit: Would there be a difference between transporting the priest to Roshar vs. a Shardblade to Egypt? There's a Steelheart WoB suggesting maybe. https://wob.coppermind.net/events/475/#e15033
No, because his brain is still dead. The flesh there still dies to the Shardblade, and without a living brain to tell his heart to beat and his lungs to breathe they won’t, which will cause him to die.
Well, yes, that seems most likely. But I'm mostly just thinking out loud. What are the limits of how self perception works on Roshar. We have at least two examples of healing being prevented by self perception. Could harm be prevented, too?
Probably in some contexts, though not one like a Shardblade. Maybe soulcasting could be resisted by someone with an especially strong Identity? Alternatively, someone who sees themself not as one person, but a collection of parts might be able to have only one part of them soulcasted.
When a shard blade cuts, it cuts not the body but the soul. So if a shardblade for example cuts the hand at the wrist it has actually sliced the hand off the soul making its physical aspect turn grey and lifeless.
Could definitely be intent, but also could be that it cuts ‘away’ from the neck since that is that your congnitive essence is located I beleive
It still works the same way as regular cutting, you don't die if your hand gets cut off. Wherever your brain and/or heart is would still be the "main" spot. And since these things work on our perception of it, there's no reason for it to be different.
Shardblades work like they do because if they didn't SLA would be rated X.
Edit: found it https://wob.coppermind.net/events/335/#e10030
True but there is also an in world explanation and set of rules for this.
Yeah, I'm just in a weird mood today.
Hope it's a good kind of weird :)
It's not, but I appreciate the thought.
Sorry to hear that. Hope you start to feel more comfortable soon.
Probabably because of center of self. In the cosmere, someone’s self has a center, which is usually their upper chest. This is the origin point for steel/iron lines, copperclouds/seeker pulses, and lots of other stuff. It can be shifted around with mental perception trickery, but my guess would be that whichever portion of the body contains the center of self is the part that remains living.
Alternatively, we could go by the rules of healing. Cosmere healing originates from the biggest chunk, so it may just be as simple as the biggest part of the body remains living.
There’s nothing special about the spine, heart, or brain, except that without them the human body doesn’t function. They’re vital points, so if they die, everything else does too. If you bisected someone without hitting any vital points, they’d live.
While a person's physical center of gravity varies depending on body shape and body type, they also have a spiritual center of gravity, located near the heart. In allomancy, this is where sight lines radiate from, ironpulls go toward, and steelpushes originate from, regardless of where the person's physical center of gravity is.
My guess is that Shardblade limb death follows a similar principle, radiating away from the person's spiritual center of gravity. This does, however, leave open the question of why a blade passing through the lower torso kills the person rather than only killing the lower body. There may be more information we don't yet know. I could speculate, but I don't think we quite have anything concrete yet.
Honestly it likely isn't the case but it could just be that when a shardblade cuts you the part of your soul with the least amount of "Mass" or "Energy" is what dies out. If you cut the arm the rest of the body still has a majority of the soul and thus doesn't get killed off. Idk it's not a great theory but I guess it makes sense.
If you cut at the neck the majority of the soul is below but the smaller amount of the soul in your head dies out killing you. Only issue with this theory is if cutting at the very end of the spine takes your legs or your upper body.
Perception as you described it is probably a fair answer.