V.
If the barbarian who swears this sinful oath were to require of the steward or of the tribune stationed on the frontier, that he, being a Christian, should give him assurance of his faithfulness to his part of the engagement about watching the crops, by the same oath which he himself has taken, involving mortal sin, does the oath pollute only that Christian man? Does it not also pollute the things regarding which he took the oath? Or if a pagan who has authority on the frontier thus give to a barbarian this oath in token of acting faithfully to him, does he not involve in the defilement of his own sin those in whose interest he swears? If I send a man to the Arzuges, is it lawful for him to take from a barbarian that sinful oath? Is not the Christian who takes such an oath from him also defiled by his sin?