As defined by the United Nation's Convention against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment, 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.
Torture as an instrument of the state to punish or extract information from individuals has a long history. In the West, the practice can be traced to the Romans, who codified the use of torture in their criminal law, believing that the torture of certain classes of society (notably, slaves) was necessary in order to ensure that they spoke the truth. During the late Middle Ages, the church in Europe banned ordeals (such as trials by fire or water) and replaced them with an inquisitional system that evaluated evidence, including written documents and confessions—the latter extracted through torture. During the 19th century, European states gradually replaced their symbols of torture with an apparatus of scientific criminology, including the police, courts, and prisons. In the modern era, there is a universal prohibition on torture under international humanitarian law (the laws of war).