  So far, we have focused on the functions criminal law fulfills in response to the commission of crime. It is plausible to think, however, that criminal law’s functions include preventing crime from occurring. We can see this by asking what success would look like for the criminal law. Would criminal law have succeeded if all thieves and murderers were tried and punished? Or would it have succeeded if there was no theft or murder, because criminalization resulted in would-be thieves and murderers refraining from such wrongs? Notice that to pose these two questions as alternatives is not to deny that punishment might be justified in preventive terms. It is rather to suggest that resorting to punishment to achieve prevention is already a partial failure for the criminal law. It is a failure to deter those who, ex hypothesi, have already committed criminal offences. Had the creation of those offences been an unqualified success, there would have been nothing for which to punish anyone.