invention of visible language ~3400 BCE in Mesopotamia
earliest form: cuneiform on clay tablets for accounting and trade records
independent inventions: Egyptian hieroglyphics (~3200 BCE), Chinese oracle bones (~1200 BCE), Mesoamerican glyphs (~600 BCE)
enabled law codes, tax records, calendars, literature, science, history
transition from oral memory to external storage of knowledge
prerequisite for every subsequent writing system: alphabets, syllabaries, logographies
the first information technology: compression of speech into persistent visual symbols
printing press (1440) and digital text (1970s) are its direct descendants
the Information Age is the latest phase of writing's ongoing revolution