If the common law is a collection of customs, who is the keeper of the customs? Advocates will naturally argue their client’s position is in line with existing custom, but only one party can be right. Of course, that person is the judge (we are putting aside, for the moment, discussions about the role of the jury and how it entered legal practice). Blackstone’s description of the role and responsibility of the judge in the common law tradition is quite interesting.
Judges, Blackstone wrote, “are the depositary of the laws; the living oracles, who must decide in all cases of doubt, and who are bound by an oath to decide according to the law of the land.” Their knowledge comes from deep experience in and study of the law—the viginti annorum lucubrationes, or twenty years’ studies. Through this long study and practice, they are “personally accustomed to the judicial decisions of their predecessors.”
This is important because judicial decisions are the lifeblood of the common law tradition. They are the proof of the existence of a custom and are preserved in public repositories for the education of future judges, advocates, and anyone literate and interested enough to learn the customs and traditions of the particular jurisdiction.
Because these decisions represent the long-standing customs and traditions of the jurisdiction, judges must be deeply committed to preserving and following precedent. They must know history. That is why the “remembrance of past events” was one of the chief qualifications of those “best instructed in the laws of their country.”
This description appears to describe a long period of study, apprenticeship, and practice in the law before one can gain the requisite education and experience to be entrusted with deciding cases.
Article III of the United States Constitution grants federal judges life tenure. Certainly, the appointment of federal judges has become—and maybe has always been—political. But training and experience still plays a role. And, at the very least, life tenure allows a judge time to build on his or her existing credentials and develop that deep understanding of the law and precedent. Also, to be fair, federal common law does not exist, so perhaps the tools of statutory construction and interpretation are as important today as history and judicial decisions were in Blackstone’s day.
Judge advocates assigned to serve an assignment as a military judge are technically federal judges because their assignment is created by a federal law and the military is a federal organization. But because they do not enjoy life tenure (and other deficiencies), they are not Article III federal judges. Though there certainly are exceptions, a vast majority of those selected to serve an assignment as a military judge are senior military officers who have spent numerous years in leadership and management assignments, not in the daily practice of military criminal law. And their 2-4 year assignment makes it less likely these officers can develop expertise similar to their Article III counterparts.
This conundrum exists at the United States Court of Appeals for the Armed Forces (CAAF) as well. This court sits atop the military justice system and is made up of five civilian judges. They are appointed by the President and confirmed by the Senate, like their federal counterparts, but they too do not enjoy life tenure and can be removed by the President. Unlike military judges, CAAF judges at least serve fifteen-year terms so at least have more time to develop expertise in military criminal law, even if their background does not include the training and experience Blackstone described.
This is not to say military trial and appellate judges, or CAAF judges, are inadequate. The very existence of a judge and an appellate review structure revolutionized the military justice system. But if the system is going to be separately maintained because it mirrors—as much as military necessity allows—its civilian counterpart, maybe it should be examined under the same standards.
 Contrast this to the Civil Code system practiced by most of Continental Europe and Louisiana. This system is Code-based, not judicial decision based, and the advocates merely assist the judge rather than engage each other in an adversarial way.