Nothing distinguishes more clearly conditions in a free country from those under arbitrary government than the observance in the former of the great principle known as the Rule of Law. Stripped of all technicalities, this means that government in all its actions is bound by rules fixed and expressed beforehand—rules which make it possible to foresee with fair certainty how the authority will use its coercive power in given circumstances and to plan one’s individual affairs on the basis of that knowledge.

-Hayek