Pacioli’s Summa de arthmetica, geometria, proportioni et proportionalita, written in Italian rather than Latin so as to be more accessible to the public, would become the first popular work on math and accounting. Its section on accounting was so well received that the publisher eventually published it as its own volume. Pacioli offered access to the precision of mathematics. “Without double entry, businessmen would not sleep easily at night,” Pacioli wrote, mixing in the practical with the technical—Pacioli’s Summa would become a kind of self-help book for the merchant class.
That a member of the clergy took an interest in double-entry bookkeeping was important, because Pacioli’s method helped the merchants overcome the church’s disdain for usury. The merchants had to prove to the church that their businesses were not, in fact, sinful, that they provided a benefit to mankind. During the Middle Ages, writes author James Aho, “the very thought that a person might be profit-hungry and yet Christian was an outrage.” Double-entry accounting, completely unintentionally, provided a way around this. How? The answer lies in the Book of Revelations, Christianity’s tale of a final reckoning, where it is said:
And I saw the dead, small and great, stand before God; and the books were opened; and another book was opened, which is the book of life; and the dead were judged out of those things which were written in the books, according to their works.
Interpretation: The dead stand before God and open their book. Then God opens his book. The second book. You might call this, oh, double bookkeeping. “Whosoever was not found written in the book of life was cast into the lake of fire.” Through a simple method of accounting, the merchant class was able to perform a trick that had eluded them for a millennium: making it acceptable to engage in the business of making loans. Double-entry bookkeeping, Aho writes, “was itself complicit in the invention of a new ‘field of visibility’: the Christian merchant.”
This deliberate connection between biblical records and accounting records is evident in Pacioli’s writings. His very first instruction in describing his double-entry method directed: “Businessmen should begin their business records with the date AD, marking every transaction so that they always remember to be ethical and, at work, always act mindful of His Holy name.”
Once usury was liberated from the Christian distrust of commerce, people began to take it up. The Medici of Florence came first, turning themselves into vital middlemen in the matching of money flows around Europe. The Medici’s breakthrough was made possible because of their consistent use of double-entry ledgers. If a merchant in Rome wanted to sell something to a customer in Venice, these new ledgers solved the problem of trust between people who lived at great distances from each other. By debiting the payer’s bank account and crediting that of the payee—with double-entry practices—the bankers were able to, in effect, move money without having to ship physical coins. In so doing, they transformed the whole enterprise of payments, setting the stage for the Renaissance and for modern capitalism itself. Just as important, they also established the 500-year practice of bankers creating an essential role for themselves as society’s centralized trust bearers.
The value of double-entry bookkeeping, therefore, wasn’t merely in dry efficiency. The ledger came to be viewed as a kind of moral compass, whose use conferred moral rectitude on all involved with it. The merchant was pious, the banker had sanctity—three popes in the sixteenth and seventeenth centuries came from the Medici family—and the trader discharged his business with veneration. Businessmen, previously mistrusted, became moral, upstanding pillars of the community. Aho writes: “Methodist Church founder John Wesley, Daniel DeFoe, Samuel Pepys, Baptist evangelicals, the deist Benjamin Franklin, the Shakers, Harmony Society, and more recently, the Iona Community in Britain, all insist that the keeping of meticulous financial accounts is part and parcel of a more general program of honesty, orderliness, and industriousness.”
Thanks to mathematical concepts imported from the Middle East during the Crusades, accounting became the moral grounding for the rise of modern capitalism, and the bean counters of capitalism became the priests of a new religion. Most (though certainly not all) people today have a hard time seeing the Bible as literal truth; but they had no trouble seeing Lehman Brothers’ books as literal truth—until the gaping inconsistencies were exposed.
The great irony of 2008 was that our belief in a system of accounting, a belief woven so deeply inside our collective psyche that we’re not even aware of it, made us vulnerable to fraud. Even when done honestly, accounting is sometimes little more than an educated guess. Modern accounting, especially at the big, international banks, has become so convoluted that it is virtually useless. In a comprehensive dissection in 2014, the Bloomberg columnist Matt Levine explained how a bank’s balance sheet is almost impossibly opaque. The “value” of a large portion of the assets on that balance sheet, he noted, is simply based on guesses made by the bank about the collectability of the loans they make, or of the bonds they hold, and the prices that they might fetch on the market, all measured against the offsetting and equally fuzzy valuation of their liabilities and obligations. If a guess is off by even 1 percent, it can turn a quarterly profit into a loss. Guessing whether a bank is actually profitable is like a pop quiz. “I submit to you that there is no answer to the quiz,” he wrote. “It is not possible for a human to know whether Bank of America made money or lost money last quarter.” A bank’s balance sheet, he said, is essentially a series of “reasonable guesses about valuation.” Make the wrong guesses, as Lehman and other troubled banks did, and you end up out of business.
Our goal here is not to trash double-entry bookkeeping or the banks. Were we to, you know, add up all the debits and credits, double-entry bookkeeping has done more good than harm. The goal really is to show the deep historical and cultural roots behind why we trusted this kind of accounting. The question now, in the wake of our fall, is whether a particular technology that allows a different kind of bookkeeping will help us renew our trust in our economic system. Can a blockchain, which is continuously open to public inspection and guaranteed not by a single bank but by a series of mathematically secured entries into a ledger that’s shared and maintained by many different computers, help us rebuild our lost social capital?
The God Protocol
On October 31, 2008, while the world was drowning in the financial crisis, a little-noticed “white paper” was released by somebody using the pen name “Satoshi Nakamoto,” and describing something called “Bitcoin,” an electronic version of cash that didn’t need state backing. At the heart of Nakamoto’s electronic cash was a public ledger that could be viewed by anybody but was virtually impossible to alter. This ledger was essentially a digitized, objective rendering of the truth, and in the years to follow it would come to be called the blockchain.
Nakamoto combined several elements to come up with his Bitcoin. But like Fibonacci and Pacioli centuries before, he wasn’t the only one working on the idea of leveraging the technology of the day to create better systems. In 2005, a computer expert named Ian Grigg, working at a company called Systemics, introduced a trial system he called “triple-entry bookkeeping.” Grigg worked in the field of cryptography, a science that dates way back to ancient times, when coded language to share “ciphers,” or secrets, first arose. Ever since Alan Turing’s calculating machine cracked the German military’s Enigma code, cryptography has underpinned much of what we’ve done in the computing age. Without it we wouldn’t be able to share private information across the Internet—such as our transactions