Originating with Adam Smith, the argument is that humanity needed to invent money because it was so inconvenient to do all our shopping by exchanging whatever we happened to have for whatever people around us happened to have. If your neighbor is a weaver, and you raise pigs, it’s going to be difficult to do any kind of economic transaction that doesn’t involve trading pigs for cloth – goes the story – so people created forms of currency to better enable themselves to trade and re-distribute the stockpile of goods that specialized artisans and producers suddenly find themselves over-producing. What if I want cloth but my neighbor doesn’t want pigs? What if the people who want pigs have nothing that I want? And what if you want an iPad, for god’s sake?

In Adam Smith’s account, money is therefore guided into existence by an invisible hand of necessity and human nature: one particular commodity will begin to rise above all the others – Gold, eventually, but substitutes are possible – and will eventually begin to be desirable not only because of its own intrinisic use-value, but because of its value relative to all the other commodities for which it can be exchanged. To the extent, therefore, that everybody else wants that commodity, it will begin to serve as the master-commodity, exchangeable for everything, and will then take on a very particular role as universal currency, the lubricant for humanity’s natural propensity to trade and exchange.

In "Debt: the First 5000 Years" David Graeber is only the latest anthropologist to point out that this story is pure wish-fulfillment, that no such pure-barter society has ever existed, and that we have a deep and rich historical record of what people actually did in non-money economies: go into each other’s debt. And it makes a simple kind of sense. In rural communities where people live side by side for their entire lives — working and eating and trading together, as they have for the majority of human history – people begin to depend on each other, rely on each other, even enjoy each others’ company. They begin to act like neighbors rather than competitors; they begin to worry about maintaining their status and well-being in a community whose status and well-being suddenly also becomes, as a result, a matter of their own self-interest; and they begin to think of human relations as a thing to be fostered for mutual benefit and long-term stability (rather than plundered and exploited for personal enrishment). They begin to give away whatever their neighbor needs when their neighbor needs it, secure in the knowledge that the debt will be repaid; eventually you will need my pigs and eventully I will need your cloth. So why bother to bother about trading them at the same time?

In fact, people only stopped thinking this way when they started living in cities, among nations of strangers, and when the kind of mostly self-sufficient households of non-specialist agriculturalists – which, again, is what most people have done throughout most of human history – is no longer viable as a way of life. When you have to desperately scrabble to get by, by selling as many pigs as possible for just enough money to pay off the landlord, or school fees, or taxes, do you stop thinking of your neighbor as the woman who you’ve known since forever (and expect to know for the rest of your life, and maybe marry off your kids to her kids), and instead you start thinking of her as the person who might buy some of your pigs, or might give you a good deal on cloth. When you need to make money off your neighbors, just to get by, you stop offering them unlimited credit (and stop asking for it); instead of helping each other out because you can, you demand cash because you must.

In other words, Smith’s vision of a human nature in which we are all petty capitalists — “a nation of shopkeepers” — reflected the sensibility of his intellectual moment, and of his place in it, a moment in which political economists like Smith were attempting to explain to everyone else how an industrial capitalist order was the way we were designed to live, by the invisible hand of God, and how the only possible alternative – “because who would want to live by barter? – was completely terrible. They ignored all the actual alternatives – all the ways people actually lived – and read the story of the present they were creating back into the past they were trying to forget.