The nature of furtum has been subjected to various interpretations, often with the assumption that this delict changed in nature between the Twelve Tables and end of the 2nd century A.D. It is submitted here that the delict was originally an intrusion upon the power (manus, potestas, dominium) of the pater familias and in its most acute form (furtum manifestum) punished with a religious sanction, viz. treating the fur as sacer. The same sanction is found in the Twelve Tables for other delicts, connected with the power of the pater familias. Since manifest furtum always implied that the fur was caught red-handed, desacralisation of the delict led to a reduction of this constellation to a mere being caught in the act. Assuming this to have been the original nature of furtum explains the forms of furtum usus and possessionis.
Generally it is assumed that caput in the phrase noxa caput sequitur refers to the delinquent slave or filius familias. The liability for the delict is attached to his person. It is argued, however, that caput refers to the pater familias of the delinquent. The Twelve Tables contained a rule on their direct and personal liability (with surrender to the autorities). The introduction of the edicts on furtum and the lex Aquilia, with the direct and exclusive liability of the pater familias for the wrongdoings of those, subjected to his potestas, led to a correction: the pater could now refuse to defend them and surrender them to the authorities, or engage in the process, with afterwards still the possibility to surrender, now to the plaintiff. The phrase as such refers then to the inclusion of the decemviral rule on liability of persons subjected to patria potestas, into the formulas for the delicts.