This understanding is also important because heavy workloads leave paroling authorities with few opportunities to discuss and debate their purposes. The main purposes of criminal sanctions are just deserts, general deterrence, incapacitation, and rehabilitation. Proponents of just deserts hold that the punishment should be proportionate to the harm done by the crime and to the blameworthiness of the offender. General deterrence rests on the assumption that those who break the law must be punished as a warning to other potential criminals. Incapacitation aims to take away the offender's opportunity to commit crimes against the public. Finally, rehabilitation sees the causes of crime within the environment of the offender and seeks to bring about changes in the individual to affect future choices about behavior. Although parole boards need not necessarily choose a single goal for their release decisionmaking and supervision responsibilities, it is important to recognize that other parts of the criminal justice system also have responsibilities for these goals and that decisionmakers should be aware of the goals being served.