But in ancient Mesopotamia, beginning around five thousand years ago, people used clay tokens to record transactions involving agricultural produce like barley or wool, or metals such as silver. Such tablets performed much the same function as a banknote. Often, through the centuries, traders have devised such tokens or bills without government involvement, especially at times when coins have been in short supply or debased and devalued.

What is the right historical analogy for all this? Allen Farrington argues that Bitcoin is to the system of fiat currencies centered around the dollar what medieval Venice once was to the remnants of the western Roman Empire, as superior an economic operating system as commercial capitalism was to feudalism. Another possibility is that the advent of blockchain-based finance is as revolutionary as that of fractional reserve banking, bond and stock markets in the great Anglo-Dutch financial revolution of the 18th century.