We all know about the tortures that took place at Abu Ghraib prison.
However, Justice Scalia explains to us that torture does not offend the US Federal Constitution.
As Justice Scalia explained to us, the Eighth Amendment says
cruel and unusual punishments [shall not be] inflicted
and torture is not punishment. In fact, as Justice Scalia explains to us, one is punished for something he/she has committed in the past. For example: "I caught my child smoking, so as a punishment I took away his mobile phone".
But "torture" is not an infliction of a damage to make the accused pay for something he/she committed in the past, or to elicit someone to refrain from committing that offense again. This is not the purpose of torture. The purpose of torture is to extort information useful for a future criminal investigation.
The explanation that Justice Scalia gave to us is consistent with the defition of punishment (remember, the Eight Amendment prohibits "cruel and unusual punishments") that BF Skinner gave to us in his operant conditioning theory:
Positive punishment: Providing a stimulus that an individual does not desire to decrease undesired behaviors. For example, a child hates to do chores. His parents will try to reduce the undesired behavior of failing a test by applying the undesired stimuli of having him do more chores around the house.
Negative punishment: Removing a stimulus that an individual desires in order to decrease undesired behaviors. For example, a child loves playing video games. His parents will try to reduce the undesired behavior of failing an exam by removing the desired stimulus of video games.
In both cases, the purpose of punishment is "to decrease undesired behaviors". The purpose of torture is not that (after all, the accused is already into custody, so he cannot committ other undesired behaviors), but to extort information useful for further prosecution or to catch other accomplices. So, also under this theory, torture is not punishment.
Moreover, as Ingraham v. Wright explains to us, the US Federal Supreme Court has "limited the application of the Eighth Amendment’s “cruel and unusual” language to criminal punishment".
A prisoner who is tortured was not subjected to criminal proceedings (in fact, the torture itself is used to extort information useful for a future criminal proceeding), let alone a criminal punishment.
Is there some legal theory, or some legal scholar, that has argued that "torture" violates the Eight Amendment to the US Federal Constitution? What would be the argument of such theory or scholar?
Is there any other legal argument that would make torture unconstitutional, on the basis on whatever constitutional provision?
Are there federal laws prohibiting torture?