Rulers could simply create their own money and spend or lend it as they saw fit. None of this was feasible until the invention of the printing press, after which the state could enforce definitions of “dollar,” “pound,” “yen,” “euro,” “yuan,” “peso,” and so on. Units of weight in gold or silver were abandoned, replaced instead by a straightforward transition to government-issued printed paper and digital fiat currency. This made it possible to increase the money supply at will. This complex transition took centuries to complete, and its consequences are becoming increasingly evident.