You suggested that it was one option among many. I agree that there are marginal cases where it may unnecessary, since people sometimes cooperate due to the pangs of conscience, but it is generally the default, not just another option.
There is nothing sadistic in thinking that people deserve punishment, not primarily for the reduction of crime, but because they have to pay for the evil they have done. It is a matter of holding people responsible for their behavior, and therefore upholding the moral order itself. Not to engage in a metaphysical discussion, it is necessary to act as if most people, most of the time, are responsible for their behavior, in order to instill expectations and internalize a sense of social obligation. If they are responsible, they must be held accountable for seriously transgressive behavior. The only way to hold them accountable is to make them pay for the crime itself, whether through fines, community service, or incarceration. |