Despite extensive debate, accounts of the Rule of Law remain strikingly vague and imprecise. This paper begins the task of remedying this situation through the development of an analytically rigorous theory of the Rule of Law. First, it offers a preliminary sketch of a concept of law; second, it shows how the principles traditionally associated with the Rule of Law can be intrinsically connected with this concept of law; and third, it shows how these principles place meaningful restrictions on what states can and cannot do. Further components of the overall project are gestured toward in the paper's conclusion. Apart from advancing the broader goal of developing a complete theory of the Rule of Law, a paper of even this limited scope will be helpful in imposing some much-needed conceptual discipline over the Rule of Law debate.