This question has to be answered, and not just because answering it is intellectually satisfying. Those who engage or want to engage in torture are constantly trying to redefine the word downwards. Nobody wants to be a torturer, but many want to use force during interrogations. because they think they have to, because they believe it helps, or simply because they’re insane and evil.
Hence, if one can manage to exclude certain forms of interrogation from the concept of “torture” by way of some definitional acrobatics, those forms become somewhat more acceptable. An example is the infamous torture definition proposed by John Yoo and the Justice Department (who, I believe, belong to the “we have to” camp):
Physical pain amounting to torture must be equivalent in intensity to the pain accompanying serious physical injury, such as organ failure, impairment of bodily function, or even death. For purely mental pain or suffering to amount to torture (under U.S. law), it must result in significant psychological harm of significant duration, e.g., lasting for months or even years. (source)
On the other hand, we don’t want the concept to cover too much. There are some cases in which the deliberate infliction of pain is justified and shouldn’t be called torture. Sadomasochistic relationships between consenting adults should not be prohibited. And some forms of criminal punishment cause pain – typically mental pain – and yet are commonly accepted. Likewise, we wouldn’t want to outlaw all types of war, no matter how intensely we yearn for peace.
So, let’s propose the following definition, based loosely on the Stanford Encyclopedia of Philosophy lemma on torture: torture is
- the intentional and non-accidental infliction of severe physical – and in some cases mental – pain or suffering (mental suffering can be a mock execution for example)
- by one person on another, non-consenting and defenseless person who may or may not be guilty of a crime (the torturer may or may not be a government official or someone employed by a government official)
- while assuming complete control over the victim’s body and autonomy
- with the purpose of:
- extracting information (forward-looking)
- extracting a confession (backward-looking)
- punishing the victim
- degrading the victim
- coercing the victim to act in a certain way or believe certain things
- terrorizing, intimidating, pacifying or oppressing the victim, or
- terrorizing, intimidating, pacifying or oppressing the wider society.
This definition is compatible with, although somewhat wider than, the definition offered in the United Nations Convention Against Torture:
Torture is any act by which severe pain or suffering, whether physical or mental, is intentionally inflicted on a male or female person for such purposes as obtaining from him, or a third person, information or a confession, punishing him for an act he or a third person has committed or is suspected of having committed, or intimidating or coercing him or a third person, or for any reason based on discrimination of any kind, when such pain or suffering is inflicted by or at the instigation of or with the consent or acquiescence of a public official or other person acting in an official capacity. It does not include pain or suffering arising only from, inherent in, or incidental to, lawful sanctions. (source)
This UN definition has the advantage of explicitly including second-order torture, namely torturing a person – for example a relative – in order to get a confession, information etc. from another person.
Both these definitions exclude, correctly I believe, acts of self-defense, masochism or other types of consensual violence, as well as violent acts between combatants and “collateral damage” (accidental injuries to civilians) in the course of war. However, it’s not because these actions are excluded from the definition of torture, that they are necessarily morally right.
More on torture here.