In this three part series the BBC is given a rare degree of access to prisons as it accompanies the Rt Rev James Jones, the Church of England's "Bishop for prisons," into the country's jails. Conversations with prisoners - voices rarely heard on radio - are the centrepieces of these programmes, but the Bishop also talks to prison staff, politicians and opinion-formers about what prison should be for, how prisoners can be helped to become useful citizens and whether community sentences can ever win the public's confidence as a viable alternative to prison.
In this first programme, James Jones visits Liverpool, High Down and Forest Bank prisons. He witnesses the "processing" of inmates as they go through prison reception (or "The Churn" ) and gets out of the way of officers on the walkways responding to alarms that are always sounding. He measures a cell (12 paces by 9). He talks to prisoners - first-timers, old hands, self-harmers - about why they are there. Governors and prison officers tell him how they seek to manage inmates' routines and behaviour, and about the importance of looking out for themselves - when two staff can be responsible for a wing holding sixty prisoners, it doesn't do to let your guard down.
The prison population is at record levels, having almost doubled in the last twenty years. The Justice secretary Kenneth Clarke says he doesn't understand how it has been allowed to get so big, and lambasts attempts of previous Governments to cut crime by giving longer sentences as "pathetic". He tells the Bishop that his aim is to reduce the re-offending rate. Yes, it will help his department's bottom line, but it's common sense too.
How to cut re-offending is the million dollar question. Prisoners, governors and commentators seem to agree that an offender only stops committing crimes when he decides he's had enough; as one said, "I've got too old for it - my heart isn't in it anymore." The deprivation of liberty, courses in thinking skills and literacy don't seem to work as effectively as the simple passage of time.
If prison doesn't reduce re-offending, does that mean it doesn't work?
Prison is also there to punish - though some say it doesn't do that well enough.
In one obvious sense prison is effective; while prisoners are locked away from society, they can't commit crime on the outside. But if prison is to mend the prisoner as well as incarcerate him, it must do more - and that is the focus of the next programme.
This programme was first broadcast on January 2nd 2012.