"Money is a collective act of the imagination, and it's a thing which we have invested our credence in, and it works because we do that," says the writer John Lanchester, author of Whoops! Why Everybody Owes Everybody and No-One Can Pay...
...But it has become clear that money has stopped working as it used to. The economic machine has seized up largely, it could be argued, because we made money too complicated and even the experts lost sight of what it really is.
John Lanchester argues that the financial whizz-kids thought they could control money and the inherent risk associated with playing about with it.
"The people inside the system were confident they had developed new tools to manage risk - that they had magically engineered away any risk.
"That is never true. Increased risk is just increased risk."
As a result, masses of cheap credit was pumped throughout the global financial system.
"The basic assumption was that the tide would not go out," says John Lanchester, "and the thing that astonished the world of money and caused the credit crunch - in fact it was the credit crunch - was the fact that the tide went out everywhere simultaneously..."
For John Lanchester, with only a little bit of tongue-in-cheek, the QE policy is an example of the world of finance once again straying from reality and entering the realms of magic.
"It's almost easier if you just say that there are elves who make money and, when the money elves get to work, they sort of magically come up with it and then there's more of it," he says.
"I think that's probably more straightforward and makes just as much sense as explaining the mechanics of quantitative easing. It's elves."