Abstract: Recent archaeological evidence supports the claim that the first system of writing and the first use of abstract numerical representation evolved from the clay token accounting system of ancient Mesopotamia. Writing and other abstract symbol systems have subsequently transformed human cognitive capacities within only few millennia, a time period too short for any substantial changes in our biologically-evolved brains. This paper uses Merlin Donald's theory of human cognitive and cultural evolution [in Origins of the Modern Mind; 1991] to identify the role played by ancient accounting in these evolutionary processes. Specifically, it is argued that this early accounting system paved the way for writing by instigating revolutionary cognitive structures for processing visual/ symbolic artifacts and establishing a primitive but very powerful form of external memory (external to the brain). The paper also explores the role that accounting systems continue to play in the provision of "cognitive scaffolding" with respect to our organizational and institutional environments, and provides a cursory overview of the pioneering developments of ancient Mesopotamien accounting in this regard.