Embodied Sensation and Oral Tradition — Humanity's Oldest Recording Device
Before the invention of writing, how did humans record knowledge and pass it to the next generation? The answer is simple. Body and voice — that was all they had.
Hunting techniques were inscribed in the body as arm movements and breathing rhythms. Knowledge of medicinal herbs was stored as smells, tastes, and the body's reactions upon ingestion. Information about dangerous places was passed down alongside the sensation of fear. All knowledge became a "record" only after passing through the body.
Oral tradition is the act of transmitting knowledge through voice. Yet it is far more than converting information into sound. The storyteller's intonation, timing, facial expressions, gestures — all of these were part of the message. Listeners received not just words but the storyteller's entire bodily presence. Oral tradition carries information that vanishes the moment you commit it to writing.
Modern humans are so accustomed to text and digital data that we have forgotten the body is itself a recording medium. Yet for the vast majority of human history, the preservation and transmission of knowledge depended on body and voice. The history of writing spans at most five thousand years. Homo sapiens have existed for three hundred thousand. Embodied sensation and oral tradition are humanity's oldest and longest-serving recording device.
Why Vendetta Wounds Took Root in the Land
In Japan's warrior society, vendetta was not mere revenge. It was the restoration of honor, an act staking a family's survival, and at times a system officially sanctioned by the shogunate. The tale of the forty-seven ronin has been retold for over three centuries not simply because it makes a good story.
There is a phenomenon in which vendetta narratives take root in specific places. "The sword fight happened on this slope." "The ambush was at this crossroads." Oral traditions tied to concrete place names are recalled every time someone walks through that land. The physical existence of a place becomes an anchor for memory. The fixation is stronger than any written record because the body performs the act of walking there.
When a descendant inherits words of pain passed down through generations, the listener's body reacts. When a grandchild hears "our grandfather was struck down here," the grandchild's body tenses almost imperceptibly. Breathing changes. Heart rate rises. Oral tradition is not transmitting information. It is propagating a bodily response.
This is the essential power of oral tradition. Text carries information. Oral tradition shakes the body. A body that has been shaken does not forget. That is why memories transmitted through oral tradition endure deeper and longer than information committed to writing.
Oral tradition does not transmit information. It propagates bodily response. A body that has been shaken does not forget.
The Ninja — A Profession of Sharpened Senses
What were ninja, really? Strip away the fictional image and what remains is a picture of people whose profession demanded the extreme use of bodily sensation.
In night combat, they had to fight relying on hearing and touch alone when vision was useless. During infiltration, they needed the skill to identify floor materials by the soles of their feet and traverse nightingale floors without making a sound. On reconnaissance missions, they had to catch distant conversations by exploiting wind direction and terrain, then carry the intelligence home.
All of these are cases where professional necessity pushed the limits of the five senses. Under ordinary circumstances, human sensory organs use only a fraction of their capacity. But when survival is at stake — when being discovered means death — the senses sharpen. Necessity unlocks the body's latent potential.
Ninja body techniques were passed from master to apprentice through oral tradition and practice. Written records were avoided for reasons of secrecy. In other words, ninjutsu was a knowledge system transmitted directly from body to body. Knowledge that cannot be committed to writing can only be stored in the body. Ninja understood this as the very foundation of their craft.
Burning It into the Eyes — Eidetic Memory as a Recording Method
Among ninja skills, eidetic memory — the ability to "burn what you see into your eyes" — stands out. The layout of an enemy castle, troop positions, terrain features. In situations where nothing could be written down, they had to memorize what they saw in an instant and bring it back.
Modern cognitive science considers eidetic memory a rare ability. Yet the ninja training system deliberately sought to develop it. Memorization drills, repetition of visual recall, concentration training through meditation — these constituted a systematic program for developing embodied knowledge.
What deserves attention is that eidetic memory lies on the extension of bodily sensation. It is not a purely intellectual operation but the refinement of the physical act of "seeing" to its extreme. The eye is a bodily organ; memory is a bodily function. Eidetic memory is the result of pushing the body's performance as a recording device to its limit.
When visceral need and life-or-death resolve converge, humans step into territory normally beyond reach. This is not a supernatural power but the body's inherent latent capacity, released by urgent necessity.
Eidetic memory is not a superpower. It is the result of life-or-death necessity pushing the precision of "seeing" — a bodily act — to its extreme.
Abilities That Develop Under the Pressure of Necessity
This is not unique to ninja. Humans develop specific abilities dramatically when driven by necessity.
A blacksmith reads temperature from subtle changes in the color of iron. Red to orange, yellow to white — these color shifts correspond to differences of tens of degrees, and the smith judges the optimal forging temperature without a thermometer. This ability has soaked into the body through thousands of repetitions.
A fisherman predicts weather changes from the shape of waves and the smell of the wind. In an era with no weather satellites or radar, survival was directly linked to the precision of bodily sensation. The accumulation of experience refines the body's sensors, forming judgment that operates below the threshold of language.
A chef's fingertips distinguish the moisture content of dough by touch. A musician's ear discerns pitch differences of a few hertz. A potter's hands feel the thickness of clay spinning on the wheel at millimeter resolution. In every case, repetition and urgency drew out the ability.
A common structure emerges. Through repeated bodily sensation, humans develop specific skills, and those skills intensify in proportion to the strength of necessity. Necessity is the greatest driving force for expanding human capability. It is not tools or technology but the situation of "having to do it" that raises the ceiling of ability.
Reaching Equivalent Skill Even After Disruption
When a skill is lost, is it gone forever? History shows otherwise.
The method for producing Damascus steel was lost in the medieval period. Yet modern metallurgists are gradually reproducing its structure through trial and error. Japanese sword-forging techniques nearly vanished after the war, but smiths who analyzed surviving blades have once again reached a high standard.
Re-attainment of skill is possible. The problem, however, is time. Reaching insights that predecessors accumulated over generations from scratch demands enormous time and trial and error. Research into reproducing Damascus steel has consumed decades and is still incomplete. For the next generation to rediscover from zero what a single artisan polished over a lifetime is a staggering inefficiency.
This fact — "re-attainment is possible, but it takes time" — is the crux of how we should think about preserving traditional techniques. If something can be reproduced after disappearing, does that mean there is no need to preserve it? Not at all. What should be preserved is the information that shortens the time to re-attainment — a reference.
Skills can be re-attained even after disruption. But whether or not you know where your predecessors arrived changes the time to get there dramatically.
Skill Transmission as Reference
If you think of skill transmission from master to apprentice as "giving answers," you miss the essence. A great master does not give answers. A great master points the direction.
"A little more to the right." "Ease the pressure there." "Stop when you hear that sound." These instructions are not complete manuals. Yet in the domain of physical action, even such imperfect guidance dramatically shortens the time to mastery. The difference in speed between relying solely on one's own bodily sensation through trial and error and having directional cues from someone experienced is an order of magnitude.
This is not limited to physical skills. In mathematical proof, the ability to construct the final proof independently is essential, but having or lacking the hint "attack from this direction and you can prove it" changes the time to arrival by worlds. In programming too, a single line of documentation can save hours of trial and error.
The power of skill transmission lies not in handing over "the answer" but in pointing "the direction." Even without a complete reproduction manual, a reference — a point of orientation — lets the learner see a path. Walking toward an invisible destination versus walking while a lighthouse beam is visible: the distance is the same, but the difficulty is entirely different.
The essence of skill transmission is showing direction, not answers. Just seeing the lighthouse beam dramatically raises the probability of arrival.
Engraving on Quartz Glass — Oral Tradition for Future Generations
Let us review the argument so far. Embodied sensation and oral tradition are humanity's oldest recording methods, and their power lies in shaking the body. Skills can be re-attained after disruption, but a reference dramatically shortens the time. Even an imperfect reproduction can be effective enough if it points the direction.
The act of engraving QR codes on quartz glass aligns precisely with this philosophy.
Quartz glass possesses physical durability exceeding a thousand years. The information engraved upon it is not a perfect reproduction. Thirty seconds of voice, a single photograph, a few lines of text — the data capacity of a QR code is severely constrained. But that is enough.
When a future generation picks up that piece of quartz glass and scans the QR code, what they find is not a complete record but a reference that points a direction. Hearing thirty seconds of an ancestor's voice does not mean knowing everything about that person. Yet the voice's inflection, breath, word choice — these contain bodily information that text alone cannot convey. Just as oral tradition shakes the body, a recorded voice shakes the body of the one who listens.
Leaving an imperfect record on a physical medium. That is equivalent to leaving a reference for future generations. Even without a perfect reproduction, pointing the direction is enough to accelerate arrival. What embodied sensation and oral tradition have accomplished over hundreds of thousands of years, quartz glass as a physical medium inherits. Digital data disappears. Servers shut down. But a record carved in stone speaks for as long as there is someone to read it.
It does not have to be a perfect reproduction. As long as a direction is shown, someone in the future will arrive. Engraving on quartz glass is the vessel that carries the philosophy of humanity's oldest recording device — body and voice — a thousand years forward.