What renders the leniency of the Congregation especially remarkable is that it was in contravention of a decree of Gregory XV, in 1623, sharpening the penalties of those entering into compacts with the demon; if they caused death by sorcery they were to be relaxed to the secular arm, even for a first offence, while, for causing impotence, or infirmity, or injury to harvests or cattle, they were to be imprisoned for life.[527] Without, of course, venturing formally to mitigate the harshness of these penalties, the Congregation could at least elude them practically, by interposing difficulties in the way of conviction, and this it did, in 1657, in a series of instructions to inquisitors. Full belief in the reality of witchcraft was assumed, but there was a hideous enumeration of the abuses through which so many innocent women were condemned. The mode of procedure prescribed was based largely on the Spanish instructions of 1614, and special stress was laid upon moderation in the use of torture, which was never to be employed until all the papers in the case had been submitted to the Congregation and its assent had been obtained, while common fame was not to be considered an indication justifying arrest. The injunction of 1593, which prohibited accepting testimony as to those seen in the Sabbat, was renewed for the reason that these assemblages were mostly an illusion and justice did not demand prosecution of those recognized through illusion.[528] While thus there was no concession in principle, in practice the persecution of witchcraft became much less deadly. A manual, dating about 1700, states that in these cases the Inquisition is accustomed to move slowly and with the greatest circumspection, for the indications are generally indirect and the _corpus delicti_ most difficult to prove. If the evidence is strong, torture is employed both for the fact and the intention; if apostasy is confessed, formal abjuration is required; if it or evil belief is denied, the abjuration is _de vehementi_; the accomplices are prosecuted, but not those named as seen in the Sabbat, on account of the illusions of the demon. Relaxation is the penalty for heretical sorcery causing death, but the difficulty of proving this is very great.[529]