Thus, in spite of considerable diversity as to incidental conditions, city and State were closely bound up with each other in the development of political society. We find no city apart from a State, and it is doubtful whether there was a State without a city as the seat and centre of its political power. But this correlation obtained only during the period of the genesis of States and of the attendant rise of the _original_ city. Once States have come into existence, many other conditions may lead to the establishment of a community which, as regards extent and relative political independence, is of the nature of a city. Such phenomena may be referred to as the _secondary_ foundation of cities; they are possible only on the basis of a previously existing political society. An approximation to original conditions occurs when a victorious State either establishes cities in the conquered provinces, centralizing in them the power over the respective territories, or transforms cities that already exist into political centres. Occurrences of this sort were frequent during the extension of Alexander's world-dominion and at the time of the Roman Empire. The same fact may be observed at a later period, in connection with the occupation of the Italian cities by the Goths and Lombards. The German cities founded during the Middle Ages differ still more widely from the original type. These cities first arose as market centres, and then gradually acquired political privileges. Thus, the process of the original foundation of cities was, as it were, reversed. In the latter case, the castle came first and the market followed; the mediæval city began as a market and reached its completion with the building of a castle. In mediæval times, however, leadership was not originally vested in the city but in rulers who occupied isolated estates scattered here and there throughout the country. Yet these secondary phenomena and their further development do not belong to our present problem of the origin of political society.
The social regulations which we have thus far considered find their consummation in the _legal system_. This possesses no content independent of the various social institutions, but merely provides certain norms of action with a social sanction. As a result, these norms are protected against violation or are designated as regulations which, whenever necessary, are defended against violators by the use of external force. Thus, the legal system does not involve the outright creation of a social order. It consists primarily in the singling out, as definite prescriptions, of certain regulations that have already arisen in the course of social life, and that are for the most part already maintained by custom. The enforcement of these regulations is expressly guaranteed by society, and means are established whereby this pledge is to be redeemed. Thus, the most important social institutions--the family, the classes, the vocations, village settlements and cities, and also the relations of property, intercourse, and contract, which these involve--were already in existence before becoming constituent parts of a legal system. Moreover, the advance beyond custom and the settlement of difficulties case by case was not made suddenly or, much less, at the same time in all regions, but came only very gradually. The formulation of laws did not, as a rule, begin in connection with the political community and then pass down to the more restricted groups, ending with the single individual. On the contrary, law began by regulating the intercourse of individuals; later, it acquired authority over family relations, which had remained under the shelter of custom for a relatively long period; last of all, it asserted itself also over the political order. That is to say, the State, which is the social organization from which the legal system took its rise, was the very last institution in connection with which objective legal forms were developed. We may account for this by reference to a factor which played an important rôle from the very outset. After the legal system had once grown up out of custom and had subjected many of the important fields of the latter to its authority, it was able of itself to create regulations, which were thus from the very beginning legal prescriptions. Such primarily legal regulations arose in connection with conditions in which, frequently, the fact that there be some law was of more importance than the precise character of the law. But even in these cases the regulations were always connected with the larger body of law that was rooted in custom. This larger body of law was but supplemented by ordinances that were called into being by temporal and cultural conditions.