What was the most effective historical instrument of torture?
As has been mentioned by ChrisDG, “effective” is an ambiguous term. The effectiveness of any particular form of torture would depend on the intent behind the torture itself. If the intent was to wrest a confession from the victim without killing, the most effective instrument would be highly dependent on the victim themselves — what they feared most, what caused them the most unbearable pain and what their body could withstand. If by “effective” you mean as a deterrent to other potential criminals, I would submit that the extended process of drawing and quartering, used primarily in England and almost exclusively reserved for traitors, was fairly horrible, though this would vary widely from country to country depending on what forms torture traditionally took in that locale. And finally if by “effective” you mean as a way to produce a slow, agonizing death, one which maximized both the pain and the period of time for which the victim had to endure it, I would have to agree that the we
