When I am dissatisfied with search results I have to dig and dig and dig. If your objective is to find some reliable information about torture, be my guest. Here are some helpful starting points.
A pragmaticist argument will link the metaphysical and logical to the scientifically demonstrable. One might argue that when the metaphysical and logical are ranged squarely against torture and the scientific observations are generally but not always in apparent agreement, the benefit of the doubt - or the abduction - should be that torture indeed does not work. And that if there are exceptions they are not worth the other results of engaging in torture as a national policy.
Here is the most celebrated modern text on the subject.
My Thoughts Are Free: MARK TWAIN ON TORTURE: "'I will tell you nothing more than I have told you; no, not even if you tear the limbs from my body. And even if in my pain I did say something otherwise, I would always say afterward that it was the torture that spoke and not I.'"
Move to the realm of observation.
When there is no unanimity, this does not mean that torture is a good idea. It means that in absolutely every case it cannot be shown that torture will not work. At which point the argument becomes, given the preponderance of evidence that torture does not work, it makes little sense to practice it as if in every case it did work, which is false.
And it calls investigation and proof of when a respectful effort to extract information has been efficacious. Such evidence is mounting.
Neuroscience:Torture Doesn't Work and Here's Why - Newsweek: "Shane O'Mara of the Trinity College Institute of Neuroscience in Dublin explains in a paper in the journal Trends in Cognitive Sciencecalled 'Torturing the Brain,' 'the use of such techniques appears motivated by a folk psychology that is demonstrably incorrect. Solid scientific evidence on how repeated and extreme stress and pain affect memory and executive functions (such as planning or forming intentions) suggests these techniques are unlikely to do anything other than the opposite of that intended by coercive or 'enhanced' interrogation.'"
Torture is not too swift in the battle to win people's hearts and minds.
Robert Fisk: Torture does not work, as history shows - Robert Fisk, Commentators - The Independent: "Grafton's conclusion is unanswerable. Torture does not obtain truth. It will make most ordinary people say anything the torturer wants. Why, who knows if the men under the CIA's 'waterboarding' did not confess that they could fly to meet the devil. And who knows if the CIA did not end up believing him."
We may well end terror by talking respectfully with the opposition in the wake of the death of Bin Laden.
Would that we were also on the verge of framing an effective argument to end the rampant militarism that hobbles the US in the effort to achieve social equity and overcome environmental challenges.
Ex-Interrogator: Torture Doesn't Work: "'It's extremely ineffective, and it's counterproductive to what we're trying to accomplish,' he told reporters. 'When we torture somebody, it hardens their resolve,' Alexander explained. 'The information that you get is unreliable ... And even if you do get reliable information, you're able to stop a terrorist attack, Al-Qaeda's then going to use the fact that we torture people to recruit new members.' Alexander says torture techniques used in Iraq consistently failed to produce actionable intelligence and that methods outlined in the US Army Field Manual, which rest on confidence building, consistently worked and gave the interrogators access to critical information"