Re:Some offenders cannot be rehabilitated (Score 1)

Of course, the modern purpose is something quite different now. For example, in California, we get Penal Code Section 1170(a) which says, in part:

The Legislature finds and declares that the purpose of imprisonment for crime is punishment. This purpose is best served by terms proportionate to the seriousness of the offense with provision for uniformity in the sentences of offenders committing the same offense under similar circumstances.

Whether this sort of thing has any tendency whatsoever to reduce crime is subject to debate.