In legal argument, every assertion cites authority: when lawyers know they are losing, they attempt to cloak weak arguments in language such as ``it is clear that’’, glossing over the insufficient basis for why; strong assertions cite controlling authority, such as a prior ruling of the U.S. Supreme Court. The same citation requirements hold true for judicial opinions. The American common law system is grounded in its constitutions and legislation, but also on the principle of stare decisis, which means a strong legal opinion will cite another, preferably higher, controlling authority for coming down on one side or another. In the absence of binding authority, non-binding or persuasive authority is relied on: someone made an argument that won a case in another jurisdiction, the judge cites that decision and the law expands to a new jurisdiction. Opponents of such decisions with weak legal precedent may deride them as ``judicial activism’’, but judge-made law is a fundamental component of how our system works, and indeed, how the legal system has managed to survive. Of course, a judge may instead reject another non-controlling decision and cite an alternative argument for ruling differently. Thus, competing legal doctrines scatter like leaves in the wind until a higher court decides to consolidate and resolve contradictory rulings. It is often possible (and enlightening) to trace a winning argument in a high court ruling down through various lower court decisions and ultimately arrive at the original language source, which can be the unprecedented argument of a jurist publishing research (and personal opinions) in some obscure law journal. Thus judge-made law, sometimes with questionable origins, becomes the law of the land and not always for the better.