> Quick, what's the difference between punishment and revenge?
John Clark offers:
> Just punishment for an evil act is the minimum action needed to prevent
> a future similar occurrence, anything more than that is revenge.
Yes, the old deterrence theory. If taken as a _defining_ property of punishment, this might indeed serve to distinguish punishment from revenge, though deterrence, when considered at all, seems usually to be bundled as a side-effect rather than being the root rationale for punishment, n'est-ce pas? But we needn't quibble over that, as I think there are serious problems with deterrence-by-penalty anyway.
First off, studies have called into question the deterrence value of sanctions, in particular that of capital punishment. There seems to be little correlation in general between either severity or sureness of punishment promised and rates of commission of the corresponding crimes.
Another problem is with measurement: by what method are we to establish the "minimum action needed", especially in view of the lack of correlation mentioned above? People vary immensely in their toleration of risks, for one thing.
To me it seems much less problematical and at any rate more cost-effective to deter by means of prevention, rather than rely on dubious after-the-fact sanctions which have only a small probability of being applied anyway (most crimes go unsolved, after all).
(Note that we've shifted the discussion away from definitional difficulties into the realm of practicality, which is probably just as well.)