Writing (circa 3400 BC)

Cuneiform writing, developed in Mesopotamia around 3400-3200 BC originally for accounting purposes, is the invention that separates prehistoric from historic humanity. Writing enabled laws to be codified, knowledge to be accumulated beyond a single lifetime, mathematics to be systematised, philosophy to be reasoned, and civilisations to coordinate at scales impossible through oral tradition alone. Without writing, there is no history — only archaeology.