If you would extract information from an interrogation subject by torture you must first make yourself an expert torturer. An inexpert torturer would impose his or her preconceptions on a subject eager for a reprieve from pain.

The only way to become an expert torturer is to begin with long study of human biology, psychology and pharmacology. Then one must progress to using torture techniques on live subjects. Authoritarian societies have little difficulty in procuring subjects, but for those of us who live in liberal democracies it is difficult to find people who can be used in training programmes as guinea pigs.

Before expending the significant training resources required to produce a qualified torturer, the wise government or private individual will be keen to ensure that candidates survive the training process without becoming psychological casualties. Only two percent of the general population has the significant psychopathic tendencies required to complete the requisite training without suffering from serious post-traumatic stress.

Only a proportion of that two percent is capable of the scientific understanding required to become a truly excellent torturer.

The difficulty with employing psychopaths is that their loyalty is difficult to gain and maintain. Indeed, it is debatable whether a true psychopath can be socialised sufficiently to maintain loyalty. This means that torturers as a group must be kept under the very tightest control. This is a demanding task for their leaders, who earn similar if not quite comparable risk of psychological collapse as a feature of the job. It is as though the psychological effects of the psychopathic subordinate are inherited by the initially well-adjusted supervisor who must keep the torturer under control.

Torturers who have successfully been trained and employed for a period of time are traditionally permitted to retire to join the community at large. This is dangerous in the same way that a tiger who has acquired a taste for human flesh is dangerous. The very predatory predisposition and violent skills that make a good torturer make that person a problematical ordinary citizen. It would be far better to confine the retired torturer in a secure mental institution suitable for people suffering from borderline personality disorder.

The information gathered through torture by anyone but the best-trained, skilled torturer must be caveatted appropriately so that intelligence analysts do not mistakenly conclude that it is reliable. Information gathered through skilled torture can perhaps be treated as at least as reliable as information gathered through ordinary intelligence-gathering means. Information gained by ordinary untrained sadism must be viewed with suspicion.

It is for the political masters of the torturers and the analysts to weigh whether the information gathered by these means is morally gotten. If one knew in advance that a subject had valuable information which could result in lives saved or state aims achieved, then this would make things easy. Sadly, the authorities who run a programme of training and using torturers must be prepared to deal a great deal of pain in return for very little result.

I have discussed the ‘ticking bomb scenario’ with many people, including army officers skilled and experienced in interrogation. The scenario is that one somehow knows that an interrogation subject knows something which, if prised out of him, could save lives. With time, the information could be gained through the painstaking process of persistent, directed questioning. In the scenario there is no time to lose: hence, the name ‘ticking bomb’. The subject is in your power, and you have some tools you could use to apply torture, perhaps some pliers or a razor blade. Do you use these means to torture the information out of the subject?

Of course this question is absurdly hypothetical. One never knows in advance what is in somebody’s head. Let us grant the premise, though: you can look through the subject’s head as though it were pellucid glass. There inside you can see the information you need, and you know that the subject has ten fingers and ten toes which are pathetically weak and puny compared with the drop-forged vanadium steel of your pliers.

One hears many different answers to the question, some especially surprising. My own answer is that if I could reliably know that my causing the subject pain would elicit God’s honest truth right away, and that countless innocent lives would be saved; then go ahead. Torture the poor blighter. Save the lives. Then go and turn yourself in for violating the law of every civilised nation. Spend the rest of your life in prison, if that’s what the judge orders. Surely twenty or thirty years eating prison porridge is as nothing compared to the lives of all those innocents?

Or did you think you should get off scot-free after breaking those knuckles, filled with your appalling moral certainty? That could only happen in the warped mind of a law professor, not anyone who respects the laws of peace and war which should apply to all mankind.

It appears that some organs of the U.S. government used torture as part of interrogation. They did so with what I would consider insufficient training to get a reliable result. They did so without appropriate screening to ensure that the torturers were psychopaths, immune from the psychological effects of their actions. This means that they have created psychological casualties, some of whom will be disabled for life. They did so without ensuring that the real psychopaths were not confined or euthanised after their service was done. This will result in violence and death in the future.

If the torture was justified because of the ‘ticking bomb’ exemption from civilised behaviour, then all those in the chain of command who authorised ‘enhanced interrogation techniques’ should put up their hands, stand trial and either enjoy exoneration or spend an appropriate period in prison.

Pretending it never happened is not an option.