Lock them up. That’s the way we’ve always dealt with offenders. Criminals deserve to be put away for their crimes. Prison works because it keeps those criminals out of circulation, and acts as society’s most effective deterrent. Our prisons may be more crowded than ever – the prison population of England and Wales, for example, has more than doubled in 20 years – but our crime rate has steadily fallen: proof, proponents of prison would argue, that incarceration works. Rehabilitation is all well and good – but the fundamental purpose of prison is to protect the public, and to punish those who have done wrong.

That’s the argument of the bang ’em up brigade; but others say that there’s a better way. New prison models have emerged in several European countries that suggest it’s not incarceration alone that prisoners need – it’s treatment for drug, alcohol, social and mental health issues. Norway, for example, has a ratio of almost one prison worker per inmate to help them overcome these problems. This system isn’t simply humane, say its advocates, it’s good for society. Just look at the statistics. In England and Wales, more than half the inmates suffer from personality disorders that our prison system doesn’t have the resources to address. Not surprisingly, 47% of inmates reoffend within a year of leaving prison. In Norway, by contrast, only 20% do. Its prison system works because it treats inmates as human beings, not criminals. Isn’t it time that we did the same?