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How Did Early Chinese Mapmakers Balance Measurement and Meaning? - The Problem of Inconsistent Maps in the Jin Dynasty | Sleepy Facts About History · Sleepy Facts About History

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Welcome to Sleepy Facts About History. In the
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3rd century CE, a Chinese official named Pei
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Shu confronted an empire's worth of maps that
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could not agree with one another. The same roads
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had different distances, and river courses diverged
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across regional records. His solution was a set
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of six principles for judging maps by measurable
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relationships. rather than by the authority of
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the mapmaker or the institution that produced
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them. This episode examines those principles,
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the administrative problems of the early Jin
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dynasty that prompted them, and the broader history
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of Chinese cartography. The discussion explores
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how practical geographic measurement coexisted
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with cosmological meaning in early China, long
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before European global exploration. Chinese mapmakers
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were combining precise spatial representation
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with symbolic significance. By looking at figures
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like Peishu, we see an official who made consistency
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itself into a cartographic goal, proposing that
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maps should expose their own errors when checked
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against the world they claim to represent. I
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wanted to understand why we often assume scientific
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cartography is a relatively recent invention.
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Looking closely at Pei Xu's work offers a different
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perspective, showing how the criteria for judging
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maps depend heavily on what a state needs them
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to do. It is a calm look at how one official
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thought about making maps that could be trusted,
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and why that question still matters today. In
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the 3rd century CE, a Chinese official named
2:00
Pei Xu confronted an empire's worth of maps that
2:04
could not agree with one another. The same roads
2:07
appeared with different distances. The same rivers
2:11
followed diverging courses. Pei Xu proposed that
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the problem was not merely error. It was the
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absence of any standard by which error could
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be identified. His solution was a set of six
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principles for judging maps by measurable relationships
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rather than by authority alone. This raises a
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question that outlives him. What does it mean
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for a map to be correct, and who decides? Most
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of us, when we think about maps, imagine a straightforward
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transaction. Someone measures the world, puts
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the measurements on paper, and the result is
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a map. We tend to assume that scientific cartography,
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the kind of map you can check, verify, and correct,
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is a relatively recent invention. We imagine
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it emerged in Europe with better instruments
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and global exploration. And if we think about
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ancient maps at all, we often sort them into
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two piles. There are the practical ones that
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tried to get things right. And there are the
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symbolic ones that were more interested in meaning
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than accuracy. Tonight, I want to introduce you
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to a 3rd century Chinese official who complicates
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all of these assumptions. His name was Pei Shu.
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He lived from 224 to 2771 CE. He served as Minister
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of Works under the early Jin Dynasty. He is remembered
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for a set of six principles that transformed
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how we might think about what a map is actually
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supposed to do. But Pei Shu did not invent mapmaking.
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He did not produce the first accurate map of
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China. He did not work in isolation, and he was
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not working with a blank slate. What he did,
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or rather, what the surviving record attributes
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to him, was to argue that maps should be judged
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by measurable relationships rather than by authority
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alone. He made consistency itself into a cartographic
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goal. And to understand why that mattered, we
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need to begin with the problem he faced. By the
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3rd century, the Chinese state had been making
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and using maps for hundreds of years. The Han
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Dynasty. which had collapsed in 220 CE just a
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few years before Pei Shu was born, had maintained
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elaborate systems of land registration, taxation,
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and military planning that depended on geographic
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records, local administrators submitted maps
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to the central government. These maps showed
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boundaries, rivers, roads, mountains, and settlements.
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They were used to assess taxes, plan campaigns,
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manage flood control, and define administrative
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jurisdictions. The state needed to know what
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it controlled. Maps were one of the tools it
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used to know it. But there was a persistent problem.
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The maps submitted from different regions often
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disagreed with one another. One map might show
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a certain distance between two cities. Another
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map, covering an adjacent region, might show
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a different distance for the same stretch of
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road. Boundaries did not line up. River courses
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diverged. Mountain passes appeared in one place
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on one map and slightly elsewhere on another.
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This was not necessarily because the mapmakers
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were incompetent. Measurement was difficult.
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Terrain varied. The instruments available were
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limited. Local officials had different priorities.
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Some were more concerned with agricultural land.
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Others focused on military routes. Others attended
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to ritual obligations. And because there was
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no common standard, each mapmaker had worked
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more or less independently. The result was a
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collection of documents that could not be easily
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reconciled. Pei Shu encountered this problem
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directly. As Minister of Works, He had access
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to the Imperial Archives and the geographic records
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accumulated from across the realm. He saw the
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inconsistencies, and he proposed something more
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systematic than simply drawing another map. He
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proposed a method. It was a set of principles
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by which maps could be made consistent with one
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another, and by which errors in existing maps
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could be identified and corrected. These principles
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are known to us from a preface attributed to
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Pei Ixiu. The preface is preserved in the Jin
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Shu, the official history of the Jin dynasty
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compiled in the 7th century, roughly 400 years
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after his death. This is a crucial point. We
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do not have Pei Shu's original map. We do not
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have a contemporary technical manual in his hand.
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What we have is a retrospective account. transmitted
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through later compilation, summarizing principles
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that Peixue was said to have articulated. We
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must treat this source carefully. It tells us
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what later historians believed Peixue had done,
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or what they found worth preserving about his
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work. It does not give us unmediated access to
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his thought. With that caution in mind, the six
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principles attributed to Peixue are these. First,
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Fenlu. Scale or proportion. This is the relationship
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between distance on the map and distance on the
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ground. Second, Xiyunwan. Orientation or directional
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reference. This is the correct relative positioning
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of places. Third, Daoli. Measured distance. This
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is the actual distance traveled along routes.
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Fourth, Jiaoxia. Elevation or relative height.
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This accounts for the fact that terrain rises
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and falls. Fifth, fang xie, squareness or angularity.
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This is the need to represent irregular shapes
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rather than forcing everything into regular forms.
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And sixth, yu xiu, straightness or curvature.
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This is the distinction between winding routes
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and straight line distances, so that a road that
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curves through mountains is not represented as
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the same length as a straight path between the
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same two points. These six principles form a
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coherent framework. They address a specific kind
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of problem. If you have two maps that disagree,
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how do you determine which one is wrong? Pei
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Xu's answer is that you check them against measurable
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relationships. Does the scale hold up? Are the
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orientations consistent? Do the measured distances
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correspond to actual travel? Does the elevation
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account for the extra length of a mountain road?
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By establishing these criteria, Peixiu was not
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merely proposing better map -making technique.
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He was proposing a standard of judgment. A map
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should not be accepted because it came from an
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authoritative source, because it had been used
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before. or because it served a particular administrative
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purpose. It should be accepted because its measurable
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relationships could be verified. This is the
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conceptual shift that makes Peishu significant.
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Before him, Chinese mapmaking had certainly involved
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measurement and practical skill. But Peishu,
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or the tradition that came to be associated with
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him, articulated something more explicit. He
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articulated the idea that consistency itself
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was a goal worth pursuing. He argued that maps
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should be designed in such a way that their errors
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would become visible when checked against other
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maps or against direct measurement. To appreciate
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what this meant, we need to look briefly at what
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Chinese mapmaking had been before Peishu. The
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evidence here comes from both transmitted texts
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and archaeological finds. One of the most remarkable
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material survivals is a set of silk maps discovered
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in 1973 at Mawangdui near modern Changsha. The
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maps were found in a Han Dynasty tomb dated to
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the 2nd century BCE, roughly 300 years before
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Pei Su. These maps depict a region in southern
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China. They show military installations, river
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systems, roads and topographic features. They
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are drawn with considerable care. Distances are
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indicated. Relative positions are maintained,
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yet they also include schematic and symbolic
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elements. Certain features are exaggerated for
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emphasis. The maps serve practical military purposes
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while also reflecting cosmological assumptions
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about the ordering of space. This combination
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is important. The Mawandui maps show that Chinese
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mapmakers before Peishu were already combining
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measured spatial information with schematic and
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symbolic elements. They combined practical military
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and administrative detail with cosmological assumptions
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about the ordering of space. They were working
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within a tradition that valued practical information,
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but they were also working within a tradition
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that did not sharply separate practical geography
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from cosmological significance. A map of territory
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was also a representation of the state's control.
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It was a representation of the cosmic order.
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It was a representation of the relationship between
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human administration and natural pattern. The
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same combination appears in the canonical texts
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that shaped geographic imagination in early China.
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The Yu Gong, or Tribute of Yu, is a chapter of
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the Shang Shu. a collection of documents that
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achieved canonical status during the Han dynasty.
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It describes the geography of the legendary Xie
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dynasty, organized into nine regions, each with
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its characteristic products and tribute obligations.
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The text is not a map, but it is a geographic
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framework. It organizes space according to political
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and ritual logic. Pei Shu explicitly referenced
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this text. His major cartographic project, the
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Yu Gong Di Yu Tu, or Map of the Tribute of Yu's
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Regions, was an 18 -sheet work that attempted
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to reconcile contemporary geographic knowledge
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with the framework of the Yu Gong. This raises
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an important question about Pei Xu's purposes.
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Was he primarily interested in practical administration?
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Or was he also engaged in a kind of canonical
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scholarship? aligning the present with a legendary
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past? The answer is likely both. The Yugong carried
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enormous authority. By mapping its regions, Pei
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Shu was not merely producing a useful administrative
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tool. He was also demonstrating that the contemporary
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world could be brought into alignment with classical
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geographic order. This was not a contradiction
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in his mind. The same map could serve multiple
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functions. It could help the state govern, and
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it could affirm the continuity between present
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administration and ancient cosmic pattern. This
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brings us to a distinction that modern listeners
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often want to make, but that we should apply
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with care. We might be tempted to sort Chinese
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maps into two categories. There are practical
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maps that try to measure space accurately, and
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there are symbolic or cosmological maps that
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were more interested in meaning than in measurement.
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Pei Xu's work is sometimes placed in the first
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category as if he were a precursor of modern
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scientific cartography struggling against the
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weight of symbolic tradition. But this is misleading.
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In the 3rd century, these categories were not
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separate in that way. A single map could be simultaneously
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practical and cosmological. The imperial capital
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might be placed at the center. not because the
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mapmaker was ignorant of its actual geographic
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position, but because centrality expressed political
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and cosmic significance. The question was not
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whether to be accurate or symbolic. The question
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was how to balance and integrate different purposes.
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Pei Su's six principles, read in this light,
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do not represent a rejection of cosmological
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mapping. They represent a formalization of one
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dimension of mapmaking. That dimension is measurable
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consistency, and it existed within a broader
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field that continued to include other dimensions.
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He was not saying that all maps must be purely
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practical. He was saying that when maps are used
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for administrative, military, or fiscal purposes,
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they should be subject to a standard of verifiable
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measurement, and he was proposing specific criteria
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by which that verification could be carried out.
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The administrative context mattered enormously
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here. The Jin Dynasty, founded by Sima Yan in
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265 CE, was attempting to reunify and stabilize
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a realm that had been fractured by the collapse
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of the Han and the period of the Three Kingdoms.
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Effective government required reliable information
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about territory. Taxes depended on knowing what
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land was arable and who controlled it. Military
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campaigns depended on knowing routes and terrain.
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The bureaucracy needed maps that could be trusted.
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And trust required some basis for checking and
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correcting errors. Pei Xu's principles addressed
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this need directly. They were not abstract philosophical
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speculations. They were a response to the practical
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problem of governing a large territorial state
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with inconsistent geographic records. Yet, we
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must be careful not to overstate what we know
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about how these principles were implemented.
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The Jun Shu preserves Pei Shu's preface and attributes
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the six principles to him. It mentions his 18
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-sheet map project. But the map itself does not
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survive. We cannot examine how he actually applied
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his principles. We do not know how widely his
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methods were adopted by other officials. We do
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not know whether they remained confined to a
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particular circle within the Jin bureaucracy.
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We do not know whether later mapmakers cited
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him because his methods were genuinely influential,
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or because his name became associated with cartographic
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authority in a more general way. The evidence
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is simply too thin for certainty. What we can
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say with confidence is that the problem Pei Xu's
17:46
identified did not go away. Chinese cartography
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continued to develop along multiple paths. Practical
17:54
administrative mapping persisted. Military cartography
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persisted. Cadastral surveying persisted. Cosmological
18:03
diagram making persisted. Later periods produced
18:07
remarkable cartographic achievements. There were
18:11
the 12th century maps carved in stone. There
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was the Yuan Dynasty geographer Zhu Siben's comprehensive
18:18
work. There was the Ming Dynasty Atlas compiled
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by Luo Hongxin in the 16th century. These later
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developments were not simply continuations of
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Peishu's method. They drew on multiple traditions.
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They adapted to new technologies and new political
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circumstances. And they maintained the coexistence
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of practical and symbolic purposes that had characterized
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Chinese mapping from its earliest surviving examples.
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Pei Xu's place in this longer history is therefore
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more specific and more modest than some earlier
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scholarship suggested. Joseph Needham in his
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monumental Science and Civilization in China
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treated Pei Xu as a foundational figure in what
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he saw as a continuous tradition of Chinese scientific
19:07
cartography. More recent scholarship, particularly
19:11
the work of Cordell Yee and others, has emphasized
19:15
the diversity of Chinese map traditions and the
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danger of reading modern scientific categories
19:20
back into pre -modern practice. Pei Shu was important,
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but he was not the single origin point of Chinese
19:28
cartography. He was one moment in a complex history.
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He was a moment when an official articulated
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with unusual clarity the idea that maps should
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be consistent and checkable. This correction
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matters for how we understand not just Peixiu,
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but the history of cartography more broadly.
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There is a persistent tendency in older narratives
19:53
to treat European cartography of the early modern
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period as the emergence of genuinely scientific
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mapping. Those narratives tend to see other traditions
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as either proto -scientific or merely symbolic.
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This framework is not sustainable once we examine
20:10
the evidence. Chinese mapmakers had been working
20:14
with scale, measurement, and spatial representation
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for centuries before the European age of exploration.
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They had developed sophisticated techniques for
20:23
administrative and military purposes. What differed
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was not the presence or absence of skill. What
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differed was the institutional contexts, the
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cosmological frameworks, and the specific problems
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that mapmakers were trying to solve. also raise
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a question that remains relevant today. What
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does it mean for a map to be correct? We might
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assume that a correct map is one that corresponds
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precisely to the territory it represents. But
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correspondence is not a simple matter. Every
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map simplifies. Every map selects. Every map
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embodies choices about what to show and what
21:08
to omit. Pei Xu's criteria scale. orientation
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measured distance elevation angularity and curvature
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do not eliminate these choices they make them
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subject to a particular kind of check if two
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maps disagree on the distance between two places
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you can measure the actual route and see which
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one is closer if a map shows a mountain pass
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of the wrong elevation travelers will find the
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discrepancy the principles do not guarantee perfect
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accuracy They create a method for identifying
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and correcting certain kinds of error. This is
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why the analogy to modern quality control is
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tempting but limited. Today we have standardized
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instruments, institutional enforcement and digital
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precision. We can specify exactly how a map should
22:01
be made and verify compliance. Pei Shu had none
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of these. He had his principles. He had his position.
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He had his access to archives, and he had his
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argument that consistency mattered. Whether his
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principles were enforced, how they were transmitted,
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and how they influenced actual practice, these
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are questions the surviving evidence does not
22:28
answer with competence. We should also consider
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what Peixue's principles did not address. They
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say nothing about projection, the mathematical
22:38
problem of representing a curved earth on a flat
22:41
surface. They say nothing about latitude and
22:44
longitude in the systematic way that later cartographers
22:48
would develop. They do not address the question
22:51
of how to represent large areas where the curvature
22:54
of the earth becomes significant. These were
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not failures of imagination. They were simply
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not the problems Pei Shu faced. The Chinese empire
23:05
was large, but its cartographic challenges were
23:08
primarily regional and administrative. The principles
23:11
he articulated were suited to the tasks at hand.
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They were suited to reconciling local maps, checking
23:18
distances, and maintaining consistent orientation
23:21
across adjacent territories. The physical form
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of his map project also deserves a moment of
23:28
attention. The Yu Gong Di Yu Tu was said to comprise
23:33
18 sheets. This was not a small, convenient reference.
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It was a substantial archive meant to be consulted
23:41
in a government office, unrolled and compared,
23:44
studied by officials who had the time and training
23:47
to work with complex geographic documents. An
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18 -sheet map on silk would have required a large
23:54
table or floor space to lay out. Silk was expensive
23:58
and durable. This made it suitable for official
24:02
archives. but it also meant that each sheet represented
24:06
a significant investment of material and labor.
24:10
Comparing maps meant handling them physically,
24:12
laying them side by side, tracing connections
24:16
across multiple sheets. The scale of the project
24:19
suggests both the ambition and the limitation
24:22
of Peixiu's work. It was comprehensive in scope,
24:27
but it was also tied to a specific institutional
24:30
setting. It was not a popular publication or
24:34
a portable guy. It was a bureaucratic instrument
24:37
designed for the needs of the state. When we
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try to picture Pei Shu at work, then, we should
24:44
imagine him not as a solitary genius in a study,
24:47
but as an official surrounded by documents. There
24:52
were silk maps, administrative reports, and canonical
24:55
texts. He compared one with another. He noted
25:00
discrepancies. He argued for a standard that
25:03
would make the discrepancies visible and correctable.
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The physical texture of this word matters. A
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silk map unrolls slowly. Its surface holds ink
25:15
with a particular saturation. The lines depicting
25:19
rivers and roads are drawn by hand with variations
25:22
that reflect the mapmaker's judgment. The maps
25:26
carry notations in lie, the standard unit of
25:29
root measurement. alongside place names and administrative
25:32
labels. This was a world in which measurement
25:36
and meaning operated together. They were not
25:40
separate categories. They were integrated aspects
25:43
of a single practice. The retrospective nature
25:47
of our sources means that we cannot know with
25:49
certainty how Pei Shu himself understood his
25:52
work. The preface preserved in the Jin Shu may
25:57
reflect his own words. or it may reflect later
26:01
editorial shaping. The 7th century compilers
26:04
had their own reasons for preserving and framing
26:07
his principles. They lived in a period when cartographic
26:11
knowledge had advanced considerably. They may
26:14
have seen in Peishu an anticipation of methods
26:17
they valued. This does not make the preface worthless.
26:21
It means we must read it as a transmitted text
26:25
shaped by multiple hands and purposes. rather
26:29
than as a transparent window into third century
26:31
practice. What remains stable across this uncertainty
26:36
is the core idea that the Seed has asked us to
26:39
examine. Pei Shu made consistency itself into
26:43
a cartographic goal. He argued that maps should
26:47
expose error through measurable relationships
26:49
rather than authority alone. This idea does not
26:53
depend on our knowing exactly how he implemented
26:56
it or how widely it was adopted. or what his
26:59
original map looked like. It is an idea that
27:03
can be traced in the surviving text, and it is
27:06
an idea that resonates with the longer history
27:09
of Chinese administrative practice. The coexistence
27:14
of practical and symbolic mapping also remains
27:16
a crucial context. We should not imagine that
27:20
Pei Xu's principles replaced cosmological diagram
27:23
making. We should not imagine that Chinese cartography
27:28
moved steadily towards scientific accuracy and
27:31
away from symbolic meaning. The two traditions
27:34
continued to coexist. A Ming Dynasty map might
27:38
include precise coastal measurements alongside
27:41
cosmological symbols. A Qing Dynasty atlas might
27:45
combine administrative detail with illustrations
27:48
of legendary geography. The purposes of maps
27:52
multiplied rather than converged. Pace, whose
27:55
contribution was to articulate one set of criteria
27:58
with unusual clarity. It was not to eliminate
28:03
the multiplicity of map traditions. This multiplicity
28:08
is worth keeping in mind when we encounter claims
28:10
about the invention of scientific cartography.
28:14
Such claims often serve national or civilizational
28:17
narratives, asserting priority for one culture
28:21
over another. The history is more interesting
28:24
and more complex than these narratives allow.
28:26
Different societies developed sophisticated spatial
28:30
representations in response to their own needs
28:33
and within their own intellectual frameworks.
28:37
The question is not who was first. The question
28:41
is what problems mapmakers faced, what resources
28:44
they had, what criteria they developed, and how
28:48
their work survived and changed over time. Pei
28:52
Xu's six principles, red in this light, are a
28:56
window into the administrative cartography of
28:59
3rd century China. They show us an official grappling
29:03
with the problem of inconsistent local maps.
29:06
They show him proposing a standard of measurable
29:09
consistency. They show him embedding that standard
29:13
within a larger framework of canonical geography
29:16
and state governance. They do not show us the
29:20
origin of all scientific cartography. They do
29:23
not show us a lone genius overcoming the limitations
29:26
of his time. They show us a moment when the problem
29:30
of consistency was articulated with particular
29:33
clarity. They show us a moment when the criteria
29:36
for judging maps were made explicit in a way
29:39
that later historians found worth preserving.
29:42
The listener who comes to this subject with modern
29:45
assumptions about maps and accuracy should leave
29:48
with a more nuanced understanding. Maps are not
29:52
simply pictures of territory. They are instruments
29:55
of governance. They are expressions of cosmological
29:59
belief. They are records of measurement. They
30:04
are products of institutional practice. The criteria
30:08
by which we judge them depend on what we want
30:11
them to do. Pei Shu wanted maps that could be
30:15
checked, corrected, and reconciled with one another
30:18
he wanted maps that would expose their own errors
30:22
when measured against the world they claimed
30:24
to represent this was not the only possible goal
30:28
for map making but it was a coherent and influential
30:31
one and it emerged from the specific administrative
30:35
needs of a large territorial state in third century
30:39
china what we cannot say is equally important
30:44
We cannot say how widely Peishu's principles
30:47
were adopted. We cannot say what his original
30:51
map looked like. We cannot say whether he was
30:54
more original than synthesizing, more innovator
30:57
than codifier. The evidence does not permit these
31:01
judgments with confidence. What it does permit
31:04
is the recognition that consistency as a cartographic
31:08
goal has a longer and more geographically distributed
31:11
history than we might assume. It also permits
31:15
the recognition that the articulation of this
31:18
goal in early China is worth understanding on
31:20
its own terms, rather than as a precursor to
31:23
European practice. The episode closes where it
31:27
began, with the problem of inconsistent maps
31:30
and the official who proposed a standard for
31:33
correcting them. Pei Xu did not invent mapmaking.
31:37
He did not create the first accurate map. He
31:41
did not single -handedly establish a tradition
31:43
of scientific cartography that would unfold unchanged
31:47
through Chinese history. What he did, or what
31:50
the retrospective record attributes to him, was
31:53
to argue that maps should be subject to a test
31:56
of measurable relationships. He argued that this
32:00
test should take precedence over the authority
32:02
of the mapmaker or the institution that produced
32:05
the map. He made consistency itself into a goal.
32:10
and in doing so, he gave later historians a rare,
32:14
explicit statement of cartographic method from
32:17
the early Chinese tradition. The principles survive
32:20
in summary form, transmitted through later compilation,
32:23
embedded in a larger world of administrative
32:26
practice and cosmological meaning. They are not
32:29
a complete technical manual. They are a glimpse
32:33
of how one official thought about the problem
32:35
of making maps that could be trusted. It is a
32:39
glimpse that remains legible across more than
32:41
17 centuries because the surviving text preserves
32:44
the argument itself, even when it cannot preserve
32:47
the map.