First, torture is likely to elicit false confessions. This is true; torture is likely to illicit false confessions and false information. Apply enough physical pain to a person and one is likely to get false information. The Inquisition established that people will admit to things that are impossible (being werewolves or witches) in order to put a stop to physical pain. Therefore, while torture should be used to gain information, information elicited by torture should not be used in prosecutions. In the United States, the Fifth Amendment protects people from involuntary self-incrimination, a protection that has been construed as a means of preventing police brutality to elicit false confessions. There is nothing incompatible with the idea of allowing the state to use torture to elicit emergency information but not allowing the state to use that information in a criminal trial. The impetus behind the use of torture is to prevent imminent harm, not promote the other interests of the criminal justice system.
The second reason that...
On some level, this is true. Some people can be trained to withstand some torture. However, pain avoidance is a very basic human drive. At some point, for the vast majority of subjects, torture will provide an effective incentive to tell the truth. Even if it does not, torture is not likely to decrease the chance of having someone tell the truth. Torture is largely effective.
For the above reasons, one should find that torture is acceptable under certain circumstances. That does not mean that torture is to be used in all scenarios or that torture is the preferred means of attaining information. On the contrary, the use of torture should be confined to those scenarios where failing to use torture would likely result in the imminent loss of life. Furthermore, information attained by torture should not be used in trial against those who were tortured. However, with those limitations, the use of torture is morally acceptable.
