I also wish to stress the need to not assume that the ideas, beliefs, or actions of an author's fictional characters are what that author himself believes or that he approves of all that his characters do. Sometimes, of course, he does--and at other times does not.
The first quote from the works of Poul Anderson showing how sensory deprivation was used to obtain information is from Chapter X of WE CLAIM THESE STARS, one of the stories he wrote for his Technic Civilization series, in the time of the Terran Empire, more than a thousand years in the future. Captain Sir Dominic Flandry, an officer in Terra's Imperial Naval Intelligence Corps, had, with guerilla assistance, captured Clanmaster Temulak, commander of the alien garrison occupying the human town of Garth, on the planet Vixen. Temulak was an officer belonging to a race called the Ardazirho which had invaded and seized Vixen, a planet colonized by humans belonging to the Empire. The Ardazirho captive was unwilling to answer questions, so Flandry took recourse to measures designed to break that resistance, using sensory deprivation. To quote from Chapter X:
He nodded to Dr. Reineke. The physician wheeled forth the equipment he had abstracted from Garth General Hospital at Flandry's request. A blindfolding hood went over Temulak's eyes, sound deadening wax filled his ears and plugged his nose, a machine supplied him with intravenous nourishment and another removed body wastes, they left him immobile and, except for the soft constant pressure of bonds and bed, sealed into a darkness like death. No sense impressions could reach him from outside. It was painless, it did no permanent harm, but the mind is not intended for such isolation. When there is nothing by which it may orient itself, it rapidly loses all knowledge of time; an hour seems like a day, and later like a week or a year. Space and material reality vanish. Hallucinations come, and the will begins to crumble. Most particularly is this true when the victim is among enemies, tensed to feel the whip or knife which his own ferocious culture would surely use.Clanmaster Temulak, a moderately high ranking Ardazirho officer, would be CERTAIN to have information which would be extremely useful for the Terrans to know. The story goes on to say Temulak finally cracked after "Three of Vixen's 22 hour rotation periods went by, and part of a fourth, before the message came that Temulak had broken" (WE CLAIM THESE STARS, Chapter XI).
In 1979, when I first read Poul Anderson's mystery MURDER IN BLACK LETTER (Macmillan: 1960), I was surprised to come across this text on page 133: "They're just now beginning to study the mental effects of eliminating sensory stimuli," said Kintyre. "The mind goes out of whack amazingly fast. My friend Levinson, in the physiology department, was telling me about some recent experiments. Volunteers, intelligent self-controlled people who knew what it's all about and knew they could quit any time they wanted--none of which applies to O'Hearn--didn't last long. Hallucinations set in." Plainly, it was in the middle or late 1950's that Anderson first came across the idea of using sensory deprivation as a means of obtaining information from subjects unwilling to truthfully answer questions.
Here we see characters from two of Poul Anderson's novels using sensory deprivation to force prisoners they knew had valuable information to answer questions truthfully. The issue to be examined is whether what Flandry and Kintyre did was torture and hence unethical or whether it was morally licit. One reason why torture as such is not used by responsible intelligence officers is because of how unreliable it can be. To again quote from one of Anderson's novels, about eight years later in the Technic History, in Chapter V of A KNIGHT OF GHOSTS AND SHADOWS, he has Flandry saying: "Let me explain from the ground up. Interrogation is an unavoidable part of police and military work. You can do it on several levels of intensity. First, simple questioning; if possible, questioning different subjects separately and comparing their stories. Next, browbeating of assorted kinds. Then torture, which can be the crude inflicting of pain or something like prolonged sleep deprivation. The trouble with these methods is, they aren't too dependable. The subject may hold out. He may lie. If he's had psychosomatic training, he can fool a lie detector; or, if he's clever, he can tell only a misleading part of the truth. At best, procedures are slow, especially when you have to crosscheck whatever you get against whatever other information you can find." We see torture, defined as either the crude inflicting of pain or prolonged sleep deprivation, dismissed as slow and unreliable.
For a look at how torture should be regarded ethically, I will quote what the CATECHISM OF THE CATHOLIC CHURCH (Image Books, 1995), an official and authoritative summarizing of Catholic doctrinal and moral teaching, says about it in Nos. 2297-2298: "2297 ....*Torture* which uses physical or moral violence to extract confessions, punish the guilty, frighten opponents, or satisfy hatred is contrary for respect for the person and for human dignity. Except when performed for strictly therapeutic, medical reasons, directly intended *amputations, mutilations, *and *sterilizations *performed on innocent persons are against the moral law." And 2298 says: "In times past, cruel practices were commonly used by legitimate governments to maintain law and order, often without protest from the Pastors of the Church, who themselves adopted in their own tribunals the prescriptions of Roman law concerning torture. Regrettable as these facts are, the Church always taught the duty of clemency and mercy. She forbade clerics to shed blood. In recent times it has become evident that these cruel practices were neither necessary for public order, nor in conformity with the legitimate rights of the human person. On the contrary, these practices led to ones even more degrading. It is necessary to work for their abolition. We must pray for the victims and their tormentors."
Given all that has been previously written, the question to be answered is whether or not the use of sensory deprivation is or is not torture. If it is not torture, or not always thus, its use as a means of extracting information from those unwilling to answer questions truthfully is ethically permissible. Those who would defend the use of sensory deprivation will point out that Temulak was not tortured in the senses given above: pain was not inflicted on him nor was he even deprived of, or prevented from sleeping. All that happened to him was being made temporarily unable to see, hear, smell, or move. And this was done only as long as it took for persuading Temulak to cooperate in being interrogated. However, those who would argue against the use of sensory deprivation as a means of obtaining information would say that having one's senses deprived of outside stimuli is torture because prolonged lack of stimulation for the senses becomes unendurable. I believe both sides would agree that to deliberately prolong sensory deprivation beyond the point of inducing the subject to cooperate in being interrogated does becomes torture, and thus immoral to use.
What conclusions can be reached to resolve this question? Sensory deprivation, when strictly limited and used solely for persuading persons being interrogated to cooperate in being questioned, can be legitimately used. Two preconditions are necessary: first, the cause or reason for using sensory deprivation on an unwilling person must be so strong that this unwillingness can be rightfully overruled. Second, interrogators must also be convinced beyond a reasonable doubt that the person they are trying to question DOES have information they need to discover (because to use sensory deprivation on a prisoner reasonably likely not to know the information being sought is indisputably torture). For example, a private will know far less information of military value than a colonel or general. That was certainly the case with Clanmaster Temulak, the captured enemy officer we see in WE CLAIM THESE STARS. Recall, Temulak was captured by Flandry and his guerrilla assistants on a planet seized and occupied by enemies, in circumstances where discovery and seizure by those enemies was a very high possibility. Flandry did not have the TIME or means for lengthy, weeks long interrogation of an unwilling prisoner.
I am, of course, open to being corrected in my view that sensory deprivation can be a legitimate interrogation method by REASONED and logical arguments. I would also be interested in finding out what professional, law abiding, and ethical interrogators and intelligence officers think of this question. I have tried to find out how sensory deprivation was used in actual cases. However, I have found none where this method was described as used with the care ordered by Flandry for the treatment of Temulak. Merely emotional or ad hominem arguments for or against sensory deprivation are rejected out of hand.
During the Troubles in Northern Ireland in the 1960's and 1970's, British security forces came to use five "sensory deprivation" methods which eventually caused the Republic of Ireland to sue the United Kingdom in the European Court of Human Rights for alleged torture of terrorists or guerrillas (see European Court of Human Rights, "Ireland v. the United Kingdom," January 18, 1978). The disputed methods were: wall standing, hooding, subjection to noise, deprivation of sleep, and deprivation of food and drink. In the final judgment handed down by the European Court in the above mentioned case, it examined the United Nations definition of torture and ruled that these five methods did not meet the intensity of pain and suffering laid down by that definition. However, the Court ruled these methods amounted to "inhuman and degrading treatment," violating Article 3 of the European Convention on Human Rights (another treaty binding on signatory nations).
Except for the hooding of Temulak, none of this applies to the case we see in WE CLAIM THESE STARS. The prisoner was not subjected to wall standing, loud noises, depriving of sleep, or depriving of nourishment. So, I am not satisfied the British case gives us a clear example in actual history of the use of sensory deprivation as seen in WE CLAIM THESE STARS. Nor have I found any US cases using "sensory deprivation" as seen in those of Poul Anderson's works I have quoted in this article. Rather, the cases I read of were roughly similar, in some of the methods used, to those seen in the British case.
And, speaking personally, I have wondered what it might be like to experience sensory deprivation. I have actually thought of being tied down, having my ears plugged, eyes blindfolded, etc., for one hour. What would it be like to endure sensory deprivation for even so short a time? I know there are persons who have found the limited use of sensory deprivation to be restful or useful.