4.0

A fascinating and thought provoking book which may have a lot of truth to it. I cannot judge if the author is stretching the evidence - I suspect he is - but he anyhow presents an important case. The steppe peoples of Eurasia have always been far more important, barbarians or not, in the development and expansion of human civilisation.
The book has a tendency to repetition with the same arguments and examples occuring more than once.