Roman lawyers made the Greek philosophical conception into a juristic theory. For the famous three precepts to which the law is reduced in Justinian's Institutes come to this: Everyone is to live honorably; he is to "preserve moral worth in his own person" by conforming to the conventions of the social order. Everyone is to respect the personality of others; he is not to interfere with those interests and powers of action, conceded to others by the social order, which make up their legal personality. Everyone is to render to everyone else his own; he is to respect the acquired rights of others. The social system has defined certain things as belonging to each individual. Justice is defined in the Institutes as the set and constant purpose of giving him these things. It consists in rendering them to him and in not interfering with his having and using them within the defined limits. This is a legal development of the Greek idea of harmoniously maintaining the social _status quo_. The later eastern empire carried it to the extreme. Stability was to be secured by rigidly keeping everyone to his trade or calling and his descendants were to follow him therein. Thus the harmony of society and the social order would not be disturbed by individual ambition. In the Middle Ages the primitive idea of law as designed only to keep the peace came back with Germanic law. But the study of Roman law presently taught the Roman version of the Greek conception and the legal order was thought of once more as an orderly maintenance of the social _status quo_. This conception answered to the needs of medieval society, in which men had found relief from anarchy and violence in relations of service and protection and a social organization which classified men in terms of such relations and required them to be held to their functions as so determined. Where the Greeks thought of a stationary society corrected from time to time with reference to its nature or ideal, the Middle Ages thought of a stationary society resting upon authority and determined by custom or tradition. To each, law was a system of precepts existing to maintain this stationary society as it was.