From Plato’s Laws:
The law enjoins that no private man shall be allowed to possess gold or silver, but only coin for daily use…our citizens should have coin passing current among themselves, but not accepted by the rest of mankind.
He was thinking about something like leather to do the trick. Paper was yet to be invented of course. Furthermore…
If a private person is ever obliged to go abroad, let him have the consent of the magistrates and go; and if when he returns he has any foreign money remaining, let him give the surplus back to the treasury, and receive a corresponding sum in the local currency. And if he is discovered to appropriate it, let it be confiscated, and let him who knows and does not inform be subject to the curse and dishonour equally with him who brought the money
Plato is famous, amongst other things, for writing in his youth The Republic, the oldest book know to describe a communist state. The older, more mature, Plato wrote The Laws, considered by some the oldest book to describe a fascist state. How much was learned in twenty-five centuries?