Torture is prohibited under international law and is widely considered a human rights violation.
Philosophical discussions about torture tend to focus on two things: whether torture is ever morally justified, and, if so, whether this should be reflected in the law. Such discussion tend to focus on extreme cases: torture the terrorist or let the bomb go off and injure hundreds or thousands of innocents. Sam Harris, in his essay “In Defense of Torture,” called these “ticking bomb” cases. Imagine the bomber sitting in your custody, gloating about the imminent explosion and the magnitude of human suffering it'll cause. Harris thinks that torturing this unpleasant fellow would be justified.
The whole ticking bomb discussion presupposes that torture is basically thought to be an unjustifiable evil to be avoided in all circumstances. Given this assumption, it is an interesting philosophical, whether we can find circumstances in which it would actually be morally acceptable.
But if what people do is a guide to what they believe, torture is not thought to be an unjustifiable evil to be avoided in all circumstances. Torture is widespread; it's an everyday occurrence.
Not just in tyrannies like Nazi Germany or Stalin’s Soviet Union. In democracies: the good old U S of A. Japan. India. France. Israel. And not just in the past. Now. And not just in Abu Ghraib or Guantanamo. In prisons, in police stations throughout the land, particularly in neighborhoods where high-priced lawyers don’t show up very often.
There is not much evidence of that torture is less frequent in democracies than in tyrannies. What's true is that democracies favor types of torture that are easier to hide and harder to prove, and are more likely to use euphemisms, like “enhanced interrogation techniques.”
This suggests that the philosophical consideration of torture should not start with ticking bomb cases. We need to start at the other end. In court, we use all sorts of inducements to get people to give evidence. We offer plea bargains, letting criminals off with comparatively light sentences in return for testimony against their confederates. We let people stew in jail, hoping to “break them down.” We offer monetary rewards for information. So we need to understand why torture is in a special category. Especially for systems that are committed to human rights and dignity. Only when we understand that, will we be in a position to consider its legitimacy in the ticking bomb case.