This is evident from a letter sent by Pope Nicholas I to Khan Boris of the Bulgars in AD 866, delivered in response to a series of questions from the former and concerned with the ongoing Christianisation of Bulgaria.
He argued for an alternative and more humane procedure, in which the accused person would be required to swear an oath of innocence upon the "holy Gospel that he did not commit [the crime] which is laid against him and from that moment on the matter is [to be put] at an end".
[2] Nicholas likewise stressed in the same letter that "those who refuse to receive the good of Christianity and sacrifice and bend their knees to idols" were to be moved towards accepting the true faith "by warnings, exhortations, and reason rather than by force," emphasising to this end that "violence should by no means be inflicted upon them to make them believe.
[2] In the High Middle Ages, the church became increasingly concerned with the perceived threat posed to its existence by resurgent heresy, in particular, that attributed to a purported sect known as the Cathars.
In 1953, in an address to the 6th International Congress of Penal Law, Pope Pius XII approvingly reiterated the position of Pope Nicholas the Great over a thousand years before him, when his predecessor had unilaterally opposed the use of judicial torture, stating: Preliminary juridical proceedings must exclude physical and psychological torture and the use of drugs: first of all, because they violate a natural right, even if the accused is indeed guilty, and secondly because all too often they give rise to erroneous results...About eleven hundred years ago, in 866, the great Pope Nicholas I replied in the following way to a question posed by a people which had just come into contact with Christianity: 'If a thief or a bandit is caught, and denies what is imputed to him, you say among you that the judge should beat him on the head with blows and pierce his sides with iron spikes, until he speaks the truth.
That, neither divine nor human law admits: the confession must not be forced, but spontaneous; it must not be extorted, but voluntary; lastly, if it happens that, after having inflicted these sufferings, you discover absolutely nothing concerning that with which you have charged the accused, are you not ashamed then at least, and do you not recognize how impious your judgment was?
Torture, which uses physical or moral violence to extract confessions, punish the guilty, frighten opponents, or satisfy hatred is contrary to respect for the person and for human dignity...
[10] In the 1990s, some activist rabbis had interpreted this statement to mean that torture could be applied against husbands in troubled marriages in order to force them into granting gittin (religious divorces) to their wives.