Why are so many rocks in the Arabian desert covered in ancient graffiti? And why is so much of this graffiti lists of ancestors? We coincidentally both read the same paper by Michael C.A. MacDonald, a complete legend, and it sparked an interesting chain of thought.

An oral society is not less sophisticated than a literate one. You lose a lot of value when you switch to literacy. In particular, you lose flexibility - in oral societies, poems for example change constantly with each retelling. New bits are added, the fat is cut, the themes are updated for the audience being addressed. The Iliad shows the power of what this process can achieve.

As a desert nomad, hospitality and cooperation between strangers is crucial. In a series ...