From Robert Stein, “Rule of Law: What Does It Mean?” (pdf):
Two seminal writings in the past century have influenced thinking about this subject. Albert Dicey, a British lawyer and scholar, addressed the meaning of the rule of law in an important book in 1885. In “The Rule of Law,” Dicey offered a definition of the words, after first noting what many other writers have noted: that the phrase is very difficult to define. Dicey concluded that the term included at least three concepts: first, the supremacy of the law as opposed to arbitrariness or even wide discretion by governments; second, the equality of all persons before the law; and third, in England, principles establishing the rights of individuals developed by case law through the centuries in that country.
Some fifty years later, Austrian economist, political theorist, and Nobel Laureate Friedrich Hayek published another influential writing adding meaning to the concept of rule of law. In 1960 Hayek wrote an important paper entitled, “The Origins of the Rule of Law,” [see F. A. Hayek, The Constitution of Liberty] tracing the history of the concept of the rule of law through many centuries. Starting with the Greek and then the Roman philosophers, the British philosophers, and the French enlightenment, Hayek identified from these writings the ideas represented by the words the rule of law. Hayek argued persuasively that this concept has been understood, expressed, and advocated by philosophers for more than two thousand years. Hayek credits Aristotle for introducing the concepts of separation of powers, predictability and superiority of law as essential characteristics of a free state …
Read the whole thing (pdf).