Hammurabi, the Silver Rule, and Why Symmetry Is Ancient

The 2008 financial crisis produced a period of intense debate about accountability, moral hazard, and the consequences of separating risk from reward. The debate was framed as a modern problem — one requiring modern solutions, modern regulations, modern frameworks.

It wasn't modern. Hammurabi solved it 3,800 years earlier.

The Builder Shall Be Put to Death

The Code of Hammurabi (circa 1750 BCE) contains a provision about construction:

"If a builder builds a house and the house collapses and causes the death of the owner — the builder shall be put to death."

The elegance of this solution is total. There's no regulator. There's no inspection agency. There's no licensing board. There's no malpractice insurance system. There's just one rule: you built it, you own the consequence.

The builder who knows this won't use substandard materials. He won't cut corners on the foundation. He won't rush the walls. Every shortcut he might take is a shortcut that will cost him his life if it fails. The incentive doesn't require enforcement — it's embedded in the outcome.

What 3,800-year-old Hammurabi understood, and what modern financial regulation has repeatedly failed to implement, is that the person making the consequential decisions must also bear the consequential risks. Remove that connection and the builder uses substandard materials, the banker takes hidden tail risks, the analyst recommends interventions he'd never personally participate in.

The Progression of Moral Symmetry

Taleb traces the development of this symmetry principle through four historical formulations, each more abstract than the last:

Lex Talionis — "an eye for an eye" (Hammurabi): Literal reciprocity. If you blind someone, you are blinded. The symmetry is mechanical and direct. This seems harsh to modern sensibility, but it has a specific virtue: it cannot be gamed. There's no ambiguity about what the consequence is.

Leviticus — "love your neighbor as yourself": Extended reciprocity. The obligation isn't just to refrain from harm but to extend care. This is a positive formulation — it tells you what to do.

The Golden Rule — "do unto others as you would have done to you": More abstract positive reciprocity. You should treat others as you'd want to be treated. This is forward-looking and aspirational.

The Silver Rule — "do not do unto others what you would not have done to you": Negative reciprocity. Don't harm others in ways you wouldn't want to be harmed.

Taleb stops at the Silver Rule. He prefers it to the Golden Rule, and his reasoning is important.

Why the Silver Rule Is More Robust Than the Golden Rule

The Golden Rule requires you to know what others want and to act on it. This creates a problem: you often don't know what others want. The person who imposes their idea of "good" on others — the reformer, the missionary, the interventionista — is following the Golden Rule as they understand it. They believe the outcome they're imposing is what others would want if they understood it correctly.

This is the intellectual structure behind most coercive do-goodism: I know what's good for you better than you do, therefore doing it to you against your will is an act of love.

The Silver Rule doesn't have this problem. It doesn't require you to know what others want. It requires you not to harm them — and you can know what harms people with much more confidence than you can know what helps them.

This is the via negativa principle in ethics: the negative is more reliable than the positive. We know the wrong with more clarity than we know the right. We can be more confident in prohibitions than in obligations.

The Practical Test

The Silver Rule provides a practical test for whether an action has skin in the game: would I want this done to me?

If you're about to give advice you wouldn't follow yourself — don't. If you're about to recommend a policy you'd oppose if it applied to you — don't. If you're about to sell a product you wouldn't buy for yourself — don't. If you're about to take a risk with other people's resources that you wouldn't take with your own — don't.

This test is simple enough to apply in real time. It doesn't require modeling all possible outcomes or weighing complex trade-offs. It just requires asking: if I were on the receiving end of what I'm about to do, would I want it?

Hammurabi Was Right About the Mechanism

The modern objection to Hammurabi's code is its harshness. Buildings collapse for reasons that aren't the builder's fault — earthquakes, floods, fires. Executing the builder for an earthquake seems unjust.

This is a fair objection to the literal application. It's not a fair objection to the principle. The principle is: whoever creates a risk must also bear the risk they create. The specific mechanism can be calibrated — death is an extreme version of liability; financial accountability, reputation consequences, and career risk are softer versions that often suffice.

What Hammurabi got right is that the mechanism must be real and proportional. If the builder has no skin in the quality of the house, the house will be built badly. If the banker has no skin in the risk of the portfolio, the portfolio will take on hidden tail risk. If the analyst has no skin in the outcome of the policy they recommend, the recommendation will be careless.

The form of accountability can be modern. The principle that creates it is ancient.

For the full framework, read Skin in the Game Explained.