Eek - Legalism is alive and well, it seems. It seems to me that we punish people primarily so that mobs with torches and pitchforks (or individuals with shotguns) don't do so. Thus, the outrage that would've been felt by the mob is echoed in the courtroom.
Um, what do you mean exactly by "Legalism"? Wikipedia has four different versions, and I don't see at a glance which one applies here :P
Cass Sunstein, David Schkade, and Daniel Kahneman, in a 1999 paper named Do People Want Optimal Deterrence, write:
If we're after optimal deterrence, we should punish potentially harmful actions more if they're hard to detect, or else the expected disutility of the punishment is too small. But apparently this does not accord with people's sense of justice.
Does this mean we should change our sense of justice? And should we apply optimal deterrence theory to informal social rewards and punishments, such as by getting angrier at antisocial behaviors that we learned of by (what the wrongdoer thought was) a freak coincidence?