"Even when judges agree on the relevance of a past case to a present one, they may, and frequently do, disagree about how the applicable precedent should be read. Thus judges construct law’s own history in the process of deciding present cases. They do so through a complex genealogical operation that accords them enormous discretion, and yet allows them to claim that they are fully and completely bound by the past. In law “the past is primarily a source of authority”-if we interpret it correctly, it will tell us how to conduct ourselves now. History is not only a source of authority but of legitimacy.” Reading and decoding the past, arguing about its meaning, and shaping decisions as if they were the inexorable product of an uncontested history is the very stuff of law. Judges make history anew with each opinion, all the while proclaiming that they are simply discovering a past whose significance is, or should be, self-evident."