Cities needed defensive walls and irrigation systems. These could be built
and maintained only by powerful rulers capable of organizing huge labor
levies. Rulers controlled labor through slavery or “corvée” (forced labor).
Forced labor was important because in societies without modern energy
supplies human beings were the most easily exploitable stores of energy.
(From the point of view of rulers, humans were living, intelligent, “batteries,”
a perspective that helps explain the pervasiveness of forced labor and slave
labor in all Agrarian civilizations.) The discovery of crude, mass-produced
beveled-rim bowls in Sumerian cities is evidence that the government
provided rations for workers or slaves. To maintain the favor of the gods,
it was necessary to build and supply temples. Indeed, in Sumer, the earliest
rulers may have been priests of some kind, as many of the earliest large
buildings seem to have been temples rather than palaces.
Rulers ruled through literate bureaucracies, powerful taxation systems,
and paid armies, features that would reappear in all tribute-taking states.
Just as farmers extracted ecological “rents” from their domesticated crops
and animals, the rulers of Sumer’s city-states collected resources from
their subjects. We call these “tributes” because, like modern taxes, they
were raised in part through the threat of coercion. New, institutionalized
hierarchies emerged, with the wealthy and powerful at the top and slaves and
war captives at the bottom.
To keep track of their growing wealth, rulers needed new methods of
accounting. These eventually evolved into the ¿ rst writing systems. At ¿ rst,
accounts were kept using tokens representing objects. Then, marks were
cut into clay using wedge-shaped papyrus stalks to represent objects such
as sheep or units of grain. The step from accounting to a writing system
that can imitate spoken language is associated with the “rebus” principle.
The Sumerian symbol for an arrow looked like an arrow. But the word for
“life” happened to sound like the word for “arrow” (“ti”), so the symbol for
arrow could be used for the more abstract idea of “life.” By early in the 3rd
millennium, such changes meant that writing could record chronicles and
even poetry, some of which can still be read today. With such huge resources,
rulers could hire paid enforcers or armies. This is the crucial step from
“power from below” to “power from above.” Much early Sumerian writing
describes wars fought by well-organized armies, and a Sumerian mosaic of