Legibility is a condition of manipulation. Any substantial state intervention in society—to vaccinate a population, produce goods, mobilize labor, tax people and their property, conduct literacy campaigns, conscript soldiers, enforce sanitation standards, catch criminals, start universal schooling—requires the invention of units that are visible. The units in question might be citizens, villages, trees, fields, houses, or people grouped according to age, depending on the type of intervention. Whatever the units being manipulated, they must be organized in a manner that permits them to be identified, observed, recorded, counted, aggregated, and monitored. The degree of knowledge required would have to be roughly commensurate with the depth of the intervention. In other words, one might say that the greater the manipulation envisaged, the greater the legibility required to effect it.
—James C. Scott, Seeing Like a State, 1998