The edicts, decrees, and rescripts came eventually to be described as “imperial constitutions” (_constitutiones principum_), and although, as we have seen, different degrees of permanence might attach to each of these methods of utterance, to a jurist of the second century they all had the force of law.[1818] From this category of enactments with binding force one important class of imperial ordinances seems formally to have been exempted. This class consisted of the _mandata_, or general instructions which the Princeps gave to officials subordinate to himself. In the early Principate they were for the most part issued to the governors of Caesar’s provinces, but the gradual encroachment of the Emperor’s powers on senatorial administration led to the mandates being issued to proconsuls as well. When the mandate dealt with a precise point of the _jus civile_ and was repeated by successive emperors, it doubtless came to have the force of a rescript;[1819] but it was more often concerned with the general administrative duties of subordinates, directing them in the doubtful cases of the moment, and, therefore, not necessarily laying down rules of perpetual validity. In one sense the mandate stands higher than the rescript, for it is as a rule more general in form, and a _mandatum_ may be the result of a series of _rescripta_ on the same point; but in another sense it stands lower, since it was understood that it might be recalled at any moment by the Princeps who had issued it, and that it might not be observed by his successor. The remarkable differences of treatment to which the Christians were subjected during the Principate was due chiefly to the fact that, so far as this treatment was a concern of the central government at all, it was one directed by mandate. A review of the powers of the Princeps as exercised through his “constitutions” and his mandates shows that he was not regarded as a true legislative authority, and that the binding force of his ordinances was technically inferior to that possessed by decrees of the Senate. But the theory of legislation was never of much practical importance at Rome. The Romans had lived for centuries mainly under the rule of interpreted or judge-made law, and now the Roman world, enlarged and unified, looked for guidance, not to the _comitia_, which were in decay, or to the Senate, whose contact with the provinces was ever becoming less, but to the one interpreter who was known to every judge and every litigant, and whose utterances could be heard at the farthest ends of the earth. It was the force of circumstances, not any constitutional theory, which made the Princeps the highest of all legislative, because the greatest of all interpreting, authorities.