The law prescribes when and how society can deal out death. The fate of rapists, murderers, enemy combatants, the unborn and the terminally ill are each governed by a certain set of legal rules. If all these rules were self-consistent then any reasonable person would find the application of their principles equivalent: that is, that the same underlying logic governs all cases.

But I don’t think this is the case. If the law were logically self-consistent then it should be possible to write an algorithm to determine the legal value of each situation. There wouldn’t be any sudden hairpin turns or surprises in the legal framework. Because the law isn’t necessarily self-consistent, but often contradictory — calling for the weighing of one set of considerations against another — society creates a body of judges who make arbitrary decisions: who arbitrate. Hence, the courts can reverse themselves, and often do, simply because a different set of people are making an arbitrary decision.

Maybe this is the least imperfect way to conduct human affairs. However that may be, it necessarily means a struggle for control over the appointment of the arbiters. The more evenly split society is on a legal issue, the more likely it is that the real process of appeal will involve who gets to select the next generation of arbiters. Some unspeakable child rape, an alteration in social attitudes, a new set of justices appointed to the bench and maybe the record spins again.