Photograph and illustrations of the Inca quipu, a knotted string recording device from the Inca culture

Date of origination: c. 600 C.E. (Andean region);
fifteenth century (Incas)

Writing systems generally have been deemed necessary achievements in the development of the world's early civilizations. Without writing, it would be impossible to keep track of the people, goods, debts, taxes and tributes, and laws of a vast empire; without records of these things, there could be no order or unity among large, diverse populations. The Incas have always stood out as the exception...