(Latin calvor, to use artifice, to deceive)
Etymologically any form of ruse or fraud employed to deceive another, particularly in judicial proceedings. In its more commonly accepted signification it means the unjust damaging of the good name of another by imputing to him a crime or fault of which he is not guilty. The sin thus committed is in a general sense mortal, just as is detraction. It is hardly necessary, however, to observe that as in other breaches of the law the sin may be venial, either because of the trivial character of the subject-matter involved or because of insufficient deliberation in the making of the accusation. Objectively, calumny is a mortal sin when it is calculated to do serious harm to the person so traduced. Just as in the instance of wrongful damage to person or estate, so the calumniator is bound to adequate reparation for the injury perpetrated by the blackening of another's goodname. He is obliged (1) to retract his false statements, and that even though his own reputation may necessarily as a consequence suffer. (2) He must also make good whatever other losses have been sustained by the innocent party as a result of his libellous utterances, provided these same have been in some measure (in confuso) foreseen by him. In canon law the phrase juramentum calumniae is employed to indicate the oathtaken by the parties to a litigation, by which they averred that the action was brought and the defence offered in good faith.