I believe that their primary purpose should be security, protecting the general population from those who have proven themselves to pose a threat to the safety or well-being of the persons or property of their fellow members of society. As far as rehabilitation goes, in my opinion that falls under the category of personal responsibility, and if someone who is in that situation is not willing to make that extra effort to rehabilitate themselves, trying to force it on them is a waste of time and money, because they obviously do not care enough about re-entering society as a useful and productive member to justify any great amount of effort on the part of the state or the prison system. That being said, I do believe that educational and vocational opportunities should be afforded to those inmates who do wish to make that extra effort.