In the first part of this paper I shall defend and elaborate upon, while only slightly modifying, what I understand to be the eore of the aeeount of the existenee of eonstitutional rules to be found in H. L. A. Hart's The Concept 0/ Law. I Stemming from a morally neutral explanation of what Hart ealls the 'internal aspeet' of the existenee of sodal norms, my aeeount oflegal authority will imply neither that those in authority have a moral right to rule nor that those over whom authority is exereised have a moral obligation to obey the law. Indeed, eontrary to what has been reeently suggested by both Neil MaeCormick2 and Gerald Postema,3 I shall even deny that offidals in authority need have, or need believe that they have, moral obligations to one another to aet in aeeordanee with the eonstitutional rules which they ean be said to aeeept. My analysis oflegal authority is thus a thoroughly positivistie one. In the seeond part of the paper I shall turn to the question of under what eonditions, if any, those with legal authority may claim a moral right to rule.