When it comes to discussing money, incomprehension is a form of consent. Illustration by Oliver Munday.

The most important mystery of ancient Egypt concerned the annual inundation of the Nile floodplain. The calendar was divided into three seasons linked to the river and the agricultural cycle it determined: akhet, or the inundation; peret, the growing season; and shemu, the harvest. The size of the harvest depended on the size of the flood: too little water, and there would be famine; too much, and there would be catastrophe; just the right amount, and the whole country would bloom and prosper. Every detail of Egyptian life was shaped by the flood. Even the tax system was based on the level of the water, which dictated how successful farmers would be in the subsequent season. Priests performed complicated rituals to divine the nature of that year’s flood and the resulting harvest. The religious élite had at their disposal a rich, emotionally satisfying mythological system; a subtle language of symbols which drew on that mythology; and a position of unchallenged power at the center of their extraordinarily stable society, one that remained in an essentially static condition for thousands of years.

But the priests were cheating, because they had something else, too: Nilometers. These were devices that consisted of large, permanent measuring stations, with lines and markers to predict the level of the annual flood, situated in temples to which only priests and rulers were granted access. Added to accurate records of flood patterns dating back for centuries, Nilometers were a necessary tool for control of Egypt. They helped give the priests and the ruling class much of their authority.

The world is full of priesthoods. On the one hand, there are the calculations that the pros make in private; on the other, elaborate ritual and language, designed to bamboozle and mystify and intimidate. To the outsider, the realm of finance looks a lot like the old Nile game. In The Economist, not long ago, I read about a German bank that had some observers worried. The journalist thought that the bank would be O.K., and that “holdings of peripheral euro-zone government bonds can be gently unwound by letting them run off.” What might that mean? There’s something kooky about the way the metaphor mixes unwinding and holding and running off, like the plot of a screwball comedy.

It’s the same when you hear money people talk about the effect of QE2 on M3, or the supply-side impact of some policy or other, or the effects of bond-yield retardation or of a scandal involving forward-settling E.T.F.s, or M.B.S.s, or subprime loans and REITs and C.D.O.s and C.D.S.s. You are left wondering whether somebody is trying to con you, or to obfuscate and blather so that you can’t tell what’s being talked about. During the recent credit crunch, many suspected that the terms for the products involved were deliberately obscure: it was hard to take in the fact that C.D.S.s were on the verge of bringing down the entire global financial system when you’d never even heard of them until about two minutes before.

Sometimes the language of finance really is obscure, and does hide the truth. The 2008 implosion featured many such terms, epitomized by financial instruments with names like “mezzanine R.M.B.S. synthetic C.D.O.” More often, though, it’s complicated because the underlying realities are complicated. The lack of transparency isn’t necessarily sinister, and has its parallel in other fields—in the world of food and wine, for instance. The French word baveuse means, literally, “drooling,” which, in the context of food, we would all agree, is not a good look. Baveuse, though, is also used to describe the texture of a perfect omelette, where the outside is cooked and the inside is set but still faintly runny. It’s a useful term to know, because it helps you to recognize the thing more easily, but the cost is that you can talk about it only with other people who also know the term.

The language of money works like that, too. It is potent and efficient, but also exclusive and excluding. Explanations are hard to hold on to, because an entire series of them may be compressed into a phrase, or even a single word.

When I was growing up, my father worked for the Hongkong and Shanghai Banking Corporation. His kind of banking wasn’t at all the fancy go-go modern investment banking that wrecked the global financial system in 2008. It involved lending to small businesses to get them started. At home, my father couldn’t bear to talk about money; his own father had been the type of control freak who uses money to express that control. If I brought up the question of my allowance, it appeared to cause him actual physical pain. On the other hand, when the subject was at one remove, he was vivacious and funny at telling stories and explaining how things worked, so much so that, forty years later, some of the things he said still make me smile. When he first joined the bank, it had a telegraphic codebook for communicating with the head office, in Hong Kong. The codebook quoted a typical message: “The marketplace is dominated by small Manchurian bears.” Dad explained that the message indicated the influence of pessimistic small-scale investors who were either based in Manchuria or had made investments there. What I liked was the image of those bears, which I imagined were like the small bears in a Tintin book, causing the market stallholders to flee in terror as they rampaged among the carts and awnings, on a furious quest for nuts and honey. Even as a child, I was struck by the fact that the decoded phrase itself was in need of further decoding. But the fact that my father worked in the world of money gave me a sense that it was, and is, comprehensible.

Many people don’t have that advantage. They feel put off or defeated by anything having to do with money and economics. It’s almost as if they didn’t have permission to understand it. I did have permission to understand it, if I wanted to, and ten or so years ago, while working on a novel about contemporary London, I began to teach myself how. One of the things that happens to you—or, at any rate, happened to me—as a novelist is that you become increasingly preoccupied with this question: What’s the story behind the evident story? In my case, the story behind the story turned out to concern money. I realized that you can’t really write a novel about London and ignore the City—London’s financial center—because finance is so integral to the place that London has become. I started to grow more curious about the economic forces behind the surface realities of life. I wrote articles on Microsoft, on Walmart, and on Rupert Murdoch. I came to think that there was a gap in the culture: most of the writing on these subjects was done either by business journalists who thought that everything about the world of business was great or by furious opponents from the left who thought that everything about it was so terrible that all that was needed was rageful denunciation. Both sides missed the complexities, and therefore the interest, of the story.