Maps, Cameras, and Ideology

Maps as diagrams are judged by how well they function, but that functionality, however it's defined, is guaranteed by the precision and accuracy that goes into the map's making.  A large part of why Captain James Cook rise from below decks to command of three exploratory expeditions to the South Pacific was his mapmaking abilities, and the maps he made were so precise and accurate, I've heard, that they were still being used in some places at the start of WW II.  This emphasis on the accuracy and precision is generally associated with scientific maps.

But there are also persuasive maps.  And with these the accuracy and precision, that is, how much of it is really needed, is measured by the function of the map. Like Marx's metaphor of the camera obscura:

If in all ideology men and their circumstances appear upside own as in a camera obscura, this phenomenon arises just as much for their historical life-process as the inversion of objects on the retina does from their physical life-process. — Karl Marx, The German Ideology, 1844, p.47

the process inverts things.  Instead of the accuracy and precision of the map being the basis for it's functionality, its functionality is the basis for how much accuracy and precision there needs to be.  With science and ideology, or to put it more generally, the inversion is from truth being the basis for acceptance to acceptance being the basis for truth.

And, the camera metaphor also holds up when we consider accuracy and precision in relation to functionless maps hanging on a wall or illustrating a book.  Perhaps the exactness has an aesthetic quality to it, but like the digital accuracy of the universe of photographs now being stored online, it has been rendered inane.