Paul Collins on how to improve the criminal justice system, and Ellie Dwight on an understaffed and ineffective probation service

In the 1990s, judges attending Judicial Studies Board seminars would hear the late David Faulkner, a humane and immensely knowledgable Home Office star, explain how German prison sentences were so much shorter than ours, with no corresponding increase in offending. Politicians, terrified of being pilloried for being soft on crime, have never taken any notice. The problem is that we have no principled national idea of what prison is for (Editorial, 12 December).

As a junior assistant recorder, I did my duty and gave long sentences to drug mules from South America, based on the ludicrous theory that the deterrent effect would resound with other potential drug mules, often semi-literate women coerced into criminal activity with no conception of the consequences. Retribution, deterrence, rehabilitation? Some shapeless idea of punishment for its own sake is the unquantifiable last refuge of the ideologically barren. But it’s all we seem to have.