Juries

 

I Fought the Law And The Law Won

I'm breakin' rocks in the hot sun
I fought the law and the law won
I fought the law and the law won

And the law used a jury.

There seems to be a misunderstanding as to why there is a jury. It is not to determine whether the law has been broken. The evidence is supposed to do that. It is to serve as a lie detector for the evidence which was admitted. A single individual might be dominant, but in error. As the number of members increases, the number of possible outcomes also.  If all of those members agree, then the evidence is probably true without error.

Dominance is backward looking. Certainty, as used in lie detecting, is forward looking. A jury should have an even number of members so that it is obvious that dominance is never an outcome since a tie is possible. If all members agree, then it is possible to use that with the number of possible outcomes, only one of which is unanimously Guilty, to compute certainty. Thus a jury of 12 members rendering a unanimous verdict of Guilty has a certainty of 99.976%, which rounds to 100.0%. Certainty is sysmetric aound a tie, such that a unanimous verdict of Not Guilty has the same certainty.  A jury of 10 members rendering the same unanimous verdict has  a certainty of only 99.902%, which rounds to 99.9%. You can never get to 100% certainty unless there are an infinite number of members on the jury, but 12 members is the fewest number that rounds to 100.0% certainty. 

The jury system may not be perfect, but it beats the alternative of trial by combat, which can only show dominance not certainty. The fact that a jury was used shows that is not a historic witch trial since those trials assumed that witches float in water and can’t drown but the innocents would drown. With a jury system the innocent does not drown, so I guess using a jury is not a witch trial.