There can be few subjects about which so many people hold stronger views, many of which are either prejudiced or ill-informed, than imprisonment. Of course, victims of crime are entitled to view perpetrators differently from others; but there is no justification for those frequently referred to as ‘hangers and floggers’, who, not knowing anything about the circumstances of those who find themselves in prison, regard every prisoner as a combination of mass murderer, paedophile, rapist and arsonist, who deserves nothing more than being locked up and the key thrown away.

Their attitude is far from the truth and distorts the purpose of imprisonment. It is often said that there are three types of people in prison – the mad, the bad and the sad – of which by far the fewest number (15% maximum) are incorrigibly bad. There have always been prisons in this country, initially holding people awaiting sentence, which, because it was corporal or capital, meant that they were not incarcerated for very long. Prisons were local, paid for by local taxes. The use of imprisonment has changed over the years, as the number of capital offences decreased, including the period when transportation was in vogue, the introduction of convict prisons, nationalisation under a Prison Commission, the abolition of the death penalty and, finally, putting it under the control of a government Ministry, first the Home Office and currently the Ministry of Justice.

The great thing about Harry Potter's book is the way that he sets about correcting the ill-informed and, by recounting the history of imprisonment and explaining the motivation and ideas of some of the giants of penal reform, educating the prejudiced. But, by deliberately bringing the history of imprisonment up to date, he is also informing the public about current issues. I am particularly pleased that he tells us so much about one of those giants, Alexander Patterson, who uttered one of the inalienable truths about imprisonment, when he said that ‘prison was punishment, it was not for punishment’. The only punishment involved is the deprivation of liberty, for a specified time, awarded by the courts following conviction for a crime. We do not practise double jeopardy in this country, and therefore it is not the job of prison officers, or prison conditions, to inflict further punishment.