The origins of money are frequently fought over. Classical economics textbooks frequently cite the idea of a barter economy switching to money for the efficiency gains. Adam Smith, in 1776, was well aware of the problems with barter economies , writing that:
One man, we shall suppose, has more of a certain commodity than he himself has occasion for, while another has less. The former consequently would be glad to dispose of, and the latter to purchase, a part of this superfluity. But if this latter should chance to have nothing that the former stands in need of, no exchange can be made between them.
The problem is, that didn't happen. David Graeber's book Debt: The First 5000 Years contains a pretty thorough demolition of the idea, noting that no anthropologist ever has found a pre-monetary society which operates a barter economy in that fashion. A few societies which have lost money for other reasons have reverted to barter, but that's a whole different thing.
Instead, Graeber writes, money arose from debt. Its first role is as a unit of account, a way of tabulating that the person who you lent a cow owes you something; then, as the amount of outstanding debt in society grows, those IOUs become tradable, and eventually standardised. You can even see that on British bank notes – they are, strictly speaking, promissory notes, representing not a sum of money, but a sum of debt. "I promise to pay the bearer, on demand…" reads the text on the front.
And now, as David Keohane excerpts over at FT Alphaville , we could be seeing that route to money creation re-occurring in Cyprus. Citi's William Buiter writes that the capital controls  imposed on the country:
Will, if they persist for more than a few weeks, likely lead to a search for alternative media of exchange for internal transactions. IOUs of large, respected enterprises could for example be countersigned and start to circulate more widely as media of exchange and means of payment. This was the case, for instance, during the 1970 bank strike in Ireland, uncleared cheques were made negotiable (like bills of exchange) and pubs and shops served as credit verifiers. These could later develop into more full-fledged parallel currencies, if internal euro liquidity in Cyprus remains very scarce.
It's also another example of how private money creation – à la Bitcoin and so many other initiatives – isn't that new or trendy at all. But the problem for groups of citizens making their own private money is that eventually they have to contend with a government.
That's not, as some of the more alarmist bitcoiners and goldbugs would have it, because the Government comes in and seizes your money if you start to rival its power. (That said, most countries do have laws on the books preventing you from minting your own coinage.) It's the more prosaic matter of taxes.
Governments have the power to demand payment of taxes in whatever currency they want – and usually, the currency they control. So while private money might grow relatively sizeable in Cyprus, no matter how organised it gets, people will always need to hold onto euros – and Bitcoin is going to struggle to get a foothold as a "real" currency if you need to convert back to pounds every April to pay HMRC.
Still, one of the few fun things about living in these interesting times is that those of us who know basic economics get to watch our textbooks played out in front of us. Northern Rock was a bank run with real queues outside the front of the building; Bitcoin lets us have a more up-to-date example of a speculator's bubble than tulip madness; and now we're seeing the origin of money in real-time.