Chapter 2: What Is Money?
Before we can understand whether clay tokens were money, we need to understand what money actually is.
This turns out to be harder than it sounds.
The Standard Definition
Economists define money by what it does:
- Medium of exchange: Money facilitates transactions
- Store of value: Money preserves purchasing power
- Unit of account: Money measures value
- Standard of deferred payment: Money enables debt
These functions are useful but incomplete. Many things can serve these functions temporarily. What makes something money rather than just a convenient trade good?
What Money Really Is
Here is a better definition.
Monetary systems are information systems that tell us who created value for other people so we can justly reward them in kind.
Money allows us to symbolize the value we created. Money is like a feather in our cap that says to everyone: "I produced value for our people."
When you work hard and sell your labor, you earn money. That money is proof you contributed. When you spend it, you are claiming your fair share in return.
This is the moral foundation of money. It connects effort to reward. It ensures those who contribute can receive.
The Counterfeiting Problem
But a problem emerges.
Some people want to steal unearned goods and services by creating fake money. If anyone can make money, those who contribute nothing can take everything. The system collapses.
Therefore, money must have strong defenses to stop counterfeiters.
How can you do this with mud?
One way is to hide secret combinations of shapes inside clay balls and keep an exact replica of the balls under the care of a trusted party who is willing to authenticate the balls any time the need arises. Simply break open both balls, examine the contents for a match, and issue a new ball with a different combination of solid shapes hidden in it.
This is exactly what the Mesopotamians did.
Self-Representing Data
Most data represents something else.
The word "apple" represents a fruit. The number "7" represents a quantity. A photograph represents a scene.
Money is different. Money represents itself.
A dollar is worth a dollar because it is a dollar. Not because it points to something else. Not because it can be exchanged for a specific commodity. Just because society agrees that this piece of data has this value.
I call this self-representing data. The data does not encode information about something external. The data is the thing it describes.
Clay tokens were self-representing data. A cone did not mean "grain." A cone meant "cone." The token did not symbolize external value. The token was the value.
"It is not at present possible to establish the meaning associated with each token type."
—MacGinnis et al., "Artifacts of Cognition"
Archaeologists could not figure out what tokens "meant" because they were asking the wrong question. Tokens did not need to mean anything beyond themselves.
Authentication Is Essential
How do you know a dollar bill is real?
You look for security features. Watermarks. Security threads. Color-shifting ink. These features prove the bill was printed by the US Mint, not by a counterfeiter with a color printer.
Authentication is what makes money valuable. Without authentication, anyone could create money. If anyone can create money, money becomes worthless.
Every monetary system in history has solved the authentication problem somehow:
- Gold coins: hard to fake the metal
- Paper money: hard to fake the printing
- Bank accounts: hard to hack the computers
- Cryptocurrency: hard to solve the cryptographic puzzles
- Clay tokens: hard to guess the random combinations
The Mesopotamians solved authentication with shared secrets. Only the legitimate owner knew what tokens were in their pouch. Only the priest knew what tokens were recorded in the impressed tablet.
The Components of a Monetary System
To evaluate any monetary system, we can examine its components:
Physical Layer: What is the money made of?
- Clay, paper, metal, bits
Data Layer: What information does money contain?
- Serial numbers, token combinations, cryptographic keys
Administrative Layer: Who validates and maintains the system?
- Priests, banks, miners, RAIDA nodes
Rules Layer: What are the rules for using money?
- Transfer mechanisms, verification procedures, counterfeiting penalties
The Theory of Perfect Money evaluates each component against three criteria:
- Confidentiality: Does the system protect privacy?
- Availability: Can money be used anytime, anywhere?
- Integrity: Is the system secure from corruption?
These same criteria applied ten thousand years ago. The Mesopotamian token system scored reasonably well on all three—at least until centralized temple states emerged and corrupted it.
Why Money Matters
Money is not just an economic tool. Money is an information system that coordinates human behavior.
What should you do when you wake up in the morning? Money tells you: get a job so you can buy food.
What job should you take? Money tells you: the one that pays most, because that is where you create most value.
What food should you buy? Money tells you: check the prices and pick what gives best value.
Without money, this coordination fails. Central planners tried to replace money with commands. Communist economies collapsed. Tens of millions starved.
Money allows billions of people to cooperate without anyone giving orders. Each person follows price signals. Collectively, we produce food, shelter, technology, art—civilization itself.
This is why the invention of money matters so much. It was not just another Neolithic innovation like pottery or weaving. It was the enabling condition for everything that followed.