Because we take it for granted
we tend to underestimate the extent to which our entire civilisation is based on the borrowing and lending of money
No, it doesn't literally make the world go round
But it does make vast quantities of people, goods and services go around the world from Babylon to Bolivia
The puzzle is that the early moneylenders got so little thanks for their services
On the contrary, they were widely reviled as pariahs
Why was that?
Welcome to Northern Italy in the year 1200AD
A land divided into multiple feuding city states
a land where trust was in rather short supply
Among the many remnants of the defunct Roman Empire
was a numerical system singularly ill-suited to complex mathematical calculation
let alone the needs of commerce