Isn't that 1491 example making for a useless definition? I'm pretty sure pre-historic is something unknown. Celts have been written about by Greeks and Romans.

Isn't that 1491 example making for a useless definition? I'm pretty sure pre-historic is something unknown. Celts have been written about by Greeks and Romans. Celts left artifacts, even ones inscribed with images, though no texts as far as I'm aware. It's not precisely prehistoric, nor precisely not. The importance of writing in the definition would be, if it came along with the spread of "civilisation", but it's a gradual thing. So I equate pre-historic with neo-lithic to pastoral lifestyle. But really, I have to click the link to find out whether its a sensationalized title or not.