He has, of course, to satisfy the Parole Board that, from the perspective of public safety, he can be released. However, he is released under licence so that monitoring can be maintained. For example, an individual may have been prompted to carry out the most violent, vicious crimes when under the influence of drugs or alcohol. Therefore, the licensing conditions may ensure that they do not revert to a life of drug dependency or alcoholism. Where there are indications that they have done so, it may be necessary to revoke the licence as they then present a danger that they would not otherwise have been seen to present when they were first released. This is an issue of proportionality and balance. To impose an absolute upon an individual in these circumstances would, I fear, impose upon him a lifetime of incarceration, in which case we would lose that balance altogether.