
The rule of law means that power should be exercised through known rules rather than personal whim. In its strongest form, it also means rulers themselves are bound by law, not placed above it.
This idea is one of civilization's great safeguards against arbitrary power. It creates the conditions for stability, fairness, contracts, and trust in institutions. Without it, politics easily slides back into personality and force.
Reference:
TaskLoco™ — The Sticky Note GOAT