Chapter 6 has a easily overlooked problem. Why did things stay so similar during the Pleistocene? Change in the climate, and presumably the local environments, didn’t spur any significant change in tools. van der Leeuw pulls that problem apart by looking at the development of short term working memory and shows there’s actually a lot of really complex cognitive processes to look at if you want to understand the manufacture of Palaeolithic hand-axes.

Chapter 12 and 13 are also thought-provoking. I like the explanation that to be social you need someone to be social with. van der Leeuw’s analysis shows that you can’t have a lone city. A city requires a community of cities. I’m more wary of collapse models of societies. It’s definitely not a brain-dead model that van der Leeuw uses, but it is very compressed. If you chart the decline from the Roman Empire from its peak around AD 200-ish to AD 500-ish that’s three centuries. On a human scale that’s the time from now back to your great-great-great-great-great-great-great-great-great-great-grandfather, assuming a grandfather is around 50 years into your past. With the distance of time I can see there is a decline but it’s less a collapse and more a gentle saunter down to the triumph of the barbarians. We could have societal collapses because we have the historical awareness and a social narrative that ancient peoples lacked.

Ironically as I was typing up that criticism, van der Leeuw was making a similar point in his conclusion. The concept of deep time provides us with a way of thinking and analysing the past in a way that the Romans couldn’t. It’s a good talk and brings together a collection of different problems and research topics into the same story. It’s a long video but worth the time.

You can watch the whole video at Fora.tv, or download the talk as an MP3 from the Long Now Foundation.