[zcfhwens] Cruel and unusual punishment

Why does the Constitution have the 8th amendment proscription of "cruel and unusual punishment"?  Here are some notes, after light research.

Prohibiting unusual punishments:

* Fairness.  Need to be able to see that the same crime is being punished the same way among different criminals, to avoid, for example, racial bias in sentencing.  (Though there's the problem that different criminals may experience the same punishment differently.  This is a problem of inequality in society.)

* Need to be able to make sure the severity of the punishment is in line with the severity of the crime.  Can only be done if punishments can be compared in standardized units.

Prohibiting cruel punishments:

* If a wrongful conviction, it must be possible to somewhat reverse the punishment.  Fines can be returned, prison sentences cut short.  But not, say, corporal punishment.  Law itself could be repealed.

Assumption is that wrongful convictions will usually be discovered quickly, thus death penalty permissable only after extensive review process.

It gets fuzzier from here.

* Carrying out a cruel punishment inflicts a social cost on the punisher (debasing human dignity), and some punishments (torture) are deemed not worth that cost no matter how effective the threat of such punishment may be as a deterrent.  If society is producing sadists for whom executing cruel punishment is not unpleasant, then that's a bigger problem that should not be rewarded with employment. (However, we certainly do have that bigger problem.)

* If the government sanctions cruel actions against criminals, it may lead to an increase in other members of society performing out those actions against each other (e.g., vigilante justice) , not all of which may be discovered and punished by law enforcement.  (This is a fairly big leap of logic.)