I began researching my most recent book, “Debt: The First 5000 Years,” in 2007, just before the great credit crisis, and as time goes by, the subject never seems to become less relevant. It’s not just the endless succession of debt crises — the subprime mortgage crisis, the credit crunch, debt ceiling crisis and European debt crisis — it is the fact that Americans have become a nation of debtors.

It is simply assumed, nowadays, that we will be born to indebted, mortgage-paying parents, go deep into debt for our educations, and never, quite, completely, get out — and, therefore, that we will both live our lives with a constant feeling of at least slight attendant fear and humiliation, and that a significant portion of our life income will end up being paid out in interest and financial service payments.

The peculiar willingness of American families to accept, at a time of 9.2 percent unemployment, that our real problem is the need to cut government spending to balance the budget can only be explained as a classic example of magical thinking (I’m an anthropologist, I know magical thinking when I see it): perhaps if we can balance our collective budget, I will be able balance my family’s budget too.

This situation might seem strange and unprecedented: but in fact, it is not. As long as there has been money, there’s been debt. It is quite likely that most people who have been alive have been debtors, at least at some point in their lives. What varies — and varies radically — over time is attitudes toward debt, and how debt crises are handled.

For one thing, what we now call “virtual money” is nothing new. In fact it’s the original form of money. Credit systems predate coinage by at least two thousand years. Human history has alternated back and forth between eras of virtual credit money, and eras dominated by gold and silver — which have also, invariably, been times of great empire, standing armies (coins were invented to pay soldiers), and slavery.

What’s more, since the dawn of recorded history, arguments over credit, debt, virtual and physical money have been at the very center of political life. At some times, particularly when money is imagined as gold, and therefore, simply one commodity among others, attitudes toward debt tended to harden, often creating dramatic social unrest (pretty much every popular insurrection in the ancient world was over issues of debt.)

In periods dominated by credit money, such as the Middle Ages, money was seen essentially as an IOU, a social arrangement. The result was, almost invariably, the creation of some sort of great institution designed to protect debtors, so as to ensure the system didn’t fly completely out of hand: periodic clean slates in the ancient Near East, bans on the charging of interest and debt peonage in Medieval Christianity and Islam, and so on.

One might argue the current age of virtual money began in 1971, when the United States went off the last traces of the gold standard — but in broad historical terms, 40 years is nothing; the new age has just begun.

The problem is we have been approaching it with increasingly outmoded assumptions: and thus, frenetically protecting creditors instead. What history shows is this is unlikely to last forever.

We already learned in 2008 that debts — even trillions in debts — can be made to go away if the debtor is sufficiently rich and influential. It is only a matter of time before people draw the obvious conclusions: that if money is just a social arrangement, so many IOUs that can be renegotiated by mutual agreement, then if democracy is to mean anything, that has to be true for everyone, not just the few.

And the implications of that, could be epochal.