Why is it that countries which have the death penalty still have to use it? If it were any sort of deterrent, once a decade would be plenty. But in fact, those regimes which are most resolutely in favour of strangling, poisoning and burning human beings, are the ones which seem to have to do it the most. The USA, Iran and China spring to mind. Far from being a deterrent, the prospect of death seems to be an encouragement to the scrambled mind of the average murderer. Which does tend to lead to the conclusion that murder is not a rational act susceptible to deterrence by the threat of civic revenge. Again, the institutionalisation of revenge can only create more murderers, if anything.
Meanwhile in Britain, a lot of newspapers and TV advertising time has been sold recently after two brutal murderer cases, and the resulting, predicatble baying for the noose to be brought back into play. The Wapping Daily Tits can hardly wait. Along with the other rags which feed of the bloodlust of the mob, it is incapable of any curiousity into the causes of things. It sees the symptom, in this case the murderer, and if he can be disappeared, the problem will disappear.
It's a quaint old attitude, and predates science of course, just as astrology and witchcraft do.
But sadly, the notion that you can cure a boil by cutting it off is not one which can run a modern society. Nowadays, since the middle of the C17th or so, we eradicate the cause of a problem, then the symptom tends to disappear.
Countries like Canada seem to have mastered the knack of applying Cause & Effect to their societies, and have reduced murder rates since they stopped strangling people to death. Why are we not able to do the same? Could it be because there is far too much money to be made from keeping the prospect within reach of those who need to fantasise on the suffering of others? Is it just another branch of the horror industry?