The correct answer is rule of law
The idea of "rule of law" is considered a structuring principle of contemporary constitutionalism, being responsible for containing arbitrary temptations to exercise State power. It reveals the main idea that the exercise of political power must always take place in accordance with the law. Illustrative is that maxim of a law that orders are not obeyed because they were given by an authority: orders are obeyed when they are in accordance with the law and were given by authorities legally vested with the power to do so.