Rules People Can Live By

The idea in plain words

A rule is useful only if people can follow it. That means they must know it exists, understand what it requires, trust that it will not change tomorrow and see it applied to others as it is applied to them. When rules are secret, vague, retroactive or enforced at whim, people cannot plan, and power becomes arbitrary even if every decision is made in good faith.

This is the idea of the rule of law. It was developed for governments, but it applies to any body that makes rules for others: platforms governing developers and sellers, companies governing employees, systems that decide on applications.

Where it comes from

The British jurist A. V. Dicey popularised the phrase in 1885, describing the rule of law as the absence of arbitrary power, equality before the law and the protection of rights through ordinary courts. In The Road to Serfdom (1944) the economist Friedrich Hayek argued that the rule of law means government bound by rules fixed and announced beforehand, so that individuals can foresee how authority will be used and plan their affairs.

The most precise account came from the American legal philosopher Lon Fuller in The Morality of Law (1964). Fuller argued that law has an inner morality of eight requirements: rules must be general, publicly promulgated, prospective rather than retroactive, clear, consistent, possible to obey, relatively constant and applied as announced. A system that fails badly on any of them, he argued, does not truly govern by rules at all.

What it does to the mind

People subject to unpredictable rules become anxious and defensive. They spend effort guessing what the rule-maker wants rather than doing good work, and they learn that relationships with the powerful matter more than merit. Predictable rules, by contrast, let people take risks and invest, because they know what they will be judged by. The perception of procedural fairness matters independently of outcomes: research on procedural justice finds that people accept unfavourable decisions more readily when the process was fair and explained.

Where it shows up

The essay on app stores tests app review against Fuller’s eight requirements and finds vague guidelines, inconsistent application and rules changed without notice. The essay on marketplaces describes sellers suspended with little explanation, and the EU’s rules requiring platforms to publish terms and give reasons. The essay on enterprise software describes rules written into code that no one could question.

What it asks of someone deciding

Use Fuller’s eight requirements as a checklist for any rule you make for others: is it known, clear, stable, consistent, possible and applied as written?

Give reasons and offer appeal. A decision explained and open to review is accepted far more readily than one that is not.

Change rules with notice and without retroactive effect. People who built on the old rules deserve time to adapt.