Literacy is the ability to use the written word to learn, teach, structurize and criticize knowledge. While every form of writing allows for passing information, proper Literacy required a physical as well as semantical infrastructure to allow knowledge to flow and accumulate: from writing equipment to schools, libraries and finally a formalized approach to knowledge, be it religion, warfare, engineering or law. Such systems unavoidably existed in all civilizations that were later labeled as great empires.