If punishment must be justified, and it must, it should be done so on the basis that morality is being restored. It is morally right and beneficial to society that people cannot get away with wrongdoing. To ensure people do not want to do wrong, weight must be given to making sure the punishment is justified on the grounds that the offender benefits to. Since deterrence did not stop them committing a crime in the first place, what would? A more moral and liberal system of punishment, surely?