[Originally posted on Mises.ca]

[Note: Many economists justify their use of unrealistic mathematical models by reference to “the map and the territory”: that mathematical models are merely a map to the territory of the real world, and that a “perfect” map wouldn’t be a map at all. The origin of this metaphor is an extremely short (only 145 words!) story called “On Exactitude in Science,” which recounts an ancient myth of map makers who made the perfect map as big as the empire, which unsurprisingly turned out to be useless. However, I have recently uncovered a second part to this legendary tale, which elaborates on what happened when the map-makers abandoned their desire for realism….]

… The New Cartographers, having long ago abandoned their obsession with exactitude, had a new focus: prediction. Thus, they crafted a System of Symbols to simplify and minimize the size of their Maps, while maximizing their predictive Power. But the Symbolism became so complex and divorced from Reality that, instead of occupying a small Corner, Map Legends occupied many Pages—and required trained Expertise for interpretation. Hiring Teams of Map Interpreters became the norm for Travelers, creating many Employment Opportunities for the New Cartographers. Yet the Maps were so confusing, that even with Professional help, Travelers still lost their way in spectacular Fashion. In fact, as the Symbolism grew more complex, and the Fees of the New Cartographers skyrocketed, more Travelers failed to ever reach their Destination. And soon, for Reasons of Self-Preservation and Economy, both the New Maps and the New Cartographers were discarded.

–Suarez Miranda, Viajes de varones prudentes, Libro IV, Cap. XLVI, Lerida, 1658