Definitions of torture: HOME PAGE
The Encyclopedia of Ethics defines torture as "the deliberate infliction of violence, and through violence, severe mental and/or physical suffering upon individuals. It may be inflicted by individuals or groups and for diverse ends, ranging from extracting information, confession, admission of culpability or liability, and self-incrimination to general persuasion, intimidation, and amusement." (quoted in Allhoff, "Terrorism and Torture," p. 105).
The definition in the UN Convention Against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment:
Article 1 (1). For the purposes of this Convention, the term "torture" means any act by which severe pain or suffering, whether physical or mental, is intentionally inflicted on a 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.
Seamus Miller: "Torture is: (a) the intentional infliction of extreme physical suffering on some non-consenting, defenceless person; (b) the intentional, substantial curtailment of the exercise of the person's autonomy (achieved by means of (a)); (c) in general, undertaken for the purpose of breaking the victim's will" (SEP "Torture").
The Definition of Torture in US Law: We might think that the definition of torture was not terribly important except for the controversy that erupted in 2002 with the infamous Bybee/Yoo Memo which defended a much narrower definition of torture. It was addressed to Alberto Gonzalez, who had "asked for our Office’s views regarding the standards of conduct under the Convention Against Torture and Other Cruel, Inhuman and Degrading Treatment or Punishment." The Office is the Office of Legal Counsel. Here is what Bybee/Yoo wrote: