rule of law
The rule of law is a simple but radical idea: nobody is above the law — not the president, not the police, not the richest person in town. The same rules apply to everyone, they're known in advance, and they're enforced the same way every time. Picture a referee who calls fouls by the rulebook no matter which team is winning, even if the team owner is shouting from the sidelines.
Why does this matter so much? Because the alternative is rule by whim — where a powerful person can lock you up, seize your home, or break a promise simply because they feel like it. When the law binds the rulers too, ordinary people can plan their lives, sign contracts, and speak freely, trusting that the rules won't change overnight to crush them.
A common misunderstanding is that the rule of law just means having lots of laws, or obeying whoever's in charge. It's the reverse: a dictator who passes cruel laws and exempts himself is the very opposite. What counts is that the law is public, applied equally, and stands above the people who wield power — including those who wrote it.
When a sitting head of state is summoned to court like any other citizen — and actually shows up — the rule of law is working.
The phrase was popularized by the British jurist A. V. Dicey in 1885, but the idea is ancient — Aristotle argued it is better to be ruled by law than by any single citizen. It is often contrasted with "rule by law," where law is merely a tool the powerful use on everyone else.