In the judicial order of criminal law of a purely accusing kind, which is still operating in medieval times, the repression of the crimen calumniae and of the offences made by the accuser in court has always constituted a powerful deterrent against an instrumental use of the trial. The Decretum of Graziano transposes a fundamental part of the law of Giustiniano envisaged for this offence, determining, on some issues, considerable affinity in the thought of the civilists and canonists of the time. This legislation provided for the repression of the offence a purely inquisitorial procedure: the judge holding the main proceedings, in fact, once ascertained that the original accusation was unsubstantiated, could prosecute ex officio the tort of calumnia immediately within the same judgement. When, therefore, Innocent III will introduce the inquisitorial procedure in the canonical penal process, the exegetes of this School already knew the validity and use for the particular case of calumnia.


Keywords: criminal law; canon law; medieval legal procedure; accusatory procedure; inquisitorial procedure; ex officio proceeding; slander.