As the first known system of writing, the cuneiform symbols traced in Sumerian clay more than six millennia ago were once regarded as a simplistic and clumsy attempt to record in linear form the sounds of a spoken language. More recently, scholars have acknowledged that early Sumerian writing - far from being a primitive and flawed mechanism that would be "improved" by the Phoenicians and Greeks - in fact represented a complete written language system, not only meeting the daily needs of economic and government administration, but also providing a new means of understanding the world. Jean-Jacques Glassner offers a compelling introduction to this seminal era in human history. Returning to early Mesopotamian texts that have been little studied or poorly understood, he traces the development of writing from the earliest attempts to the sophisticated system of roughly 640 signs that comprised the Sumerian repertory by about 3200 BC. Glassner further argues - with an occasional nod to Derrida - that the invention of writing had a deeper metaphysical significance. By bringing the divinely ordained spoken language under human control, Sumerians were able to "make invisibility visible", separating themselves from the divine order and creating a new model of power.