The 1783 map Chikyū ichiranzu by Genran Nakane, shows several aspects that support David Turnbull’s quote from his book Maps Are Territories where he says that “maps are theories and they are socially and culturally constructed.”
Firstly, we can see that Japan is not only centred in the middle of the map as the focus point, but it is also much bigger than its actual size, especially in comparison to other countries such as China. The cartographer’s choices show an intentional or unintentional bias and reflect the idea that Japan has higher importance than the other countries.
While the choice of size for Japan might simply have been a practical one, made to fit the different prefectures on the map, it would still show subconscious social and cultural constructs. Japan has enough cultural importance to the cartographer that they felt the need to further divide it into prefectures while they did not feel the need to do that for other places. Except for Japan, the only country that is further divided is China, which, except for the Dutch East India Company, was Japan’s only trading partner at that time.
Beyond that, the concept of borders itself, may it be between prefectures or countries, is socially and culturally constructed. These borders are not physical barriers most of the time (with the exception of mountain ranges, rivers or oceans perhaps) – they can only exist if people give them the social and cultural significance to exist. Nothing will stop a person from crossing borders between different countries other than another person who is made to believe that these borders exist in the first place.
It is also interesting that Europe is the least detailed continent. Surprisingly, the Netherlands is not highlighted, even though the Dutch East India Company was one of Japan’s very few trade partners. The United Kingdom and Ireland, on the other hand, are distinct from the rest of Europe even though there was no formal relationship. The blankness of Europe could also be a culturally constructed part of the map. As the area where the Jesuit missionaries had come from, it could have intentionally been left less detailed since the map was made more than 100 years after the ban on Christianity had been put in place.Perhaps showing less interest in the region was an approach taken due to persecution of Christians that had already been rooted in society and the possible subsequent diffidence of Europe. The only other area that is also not detailed is the big area on the bottom of the map below that I can only guess to be Antarctica (even though it expands all the way up to Asia, engulfing the area Australia would be found in).
I could not find a map legend, or at least not one that I could understand, making the map only accessible to people of the same cultural sphere as the cartographer. It was meant for people who either spoke and could read the same language or who would have understood the map based on shared cultures and understandings.