Transition from the idea of law as a device to keep the peace to the idea of law as a device to maintain the social _status quo_ may be seen in the proposition of Heraclitus, that men should fight for their laws as for the walls of their city. In Plato the idea of maintaining the social order through the law is fully developed. The actual social order was by no means what it should be. Men were to be reclassified and everyone assigned to the class for which he was best fitted. But when the classification and the assignment had been made the law was to keep him there. It was not a device to set him free that he might find his own level by free competition with his fellows and free experiment with his natural powers. It was a device to prevent such disturbances of the social order by holding each individual to his appointed place. As Plato puts it, the shoemaker is to be only a shoemaker and not a pilot also; the farmer is to be only a farmer and not a judge as well; the soldier is to be only a soldier and not a man of business besides; and if a universal genius who through wisdom can be everything and do everything comes to the ideal city-state, he is to be required to move on. Aristotle puts the same idea in another way, asserting that justice is a condition in which each keeps within his appointed sphere; that we first take account of relations of inequality, treating individuals according to their worth, and then secondarily of relations of equality in the classes into which their worth requires them to be assigned. When St. Paul exhorted wives to obey their husbands, and servants to obey their masters, and thus everyone to exert himself to do his duty in the class where the social order had put him, he expressed this Greek conception of the end of law.