But are any of them strictly local in nature? The main streets of the city are arteries of traffic which link up with the state highways; were it not for the speed-limit signs, it would be difficult to tell where one class of streets ends and the other begins. The city police enforce the state laws and it is hardly plausible to urge that the state legislature shall have no control over the enforcement of its own statutes. The work of the city police is not, therefore, a matter of strictly local concern. So it is with health regulation, water supply, education, poor-relief, and many other municipal functions. The state cannot allow the children of any community to grow illiterate; it cannot afford to take the risk of an epidemic through the defective care of the public health in some negligent city; and it cannot fairly be expected to stand by idly when a city neglects the sick or the poor because its taxpayers wish to save money. Municipal home rule, if it were permitted to cover all these things, would be another name for local chaos. The relations between a city and the surrounding country are so intimate, and each depends so much upon the other, that no rigid line of separation between local and general interests can be drawn. To make every city a little sovereign republic, wrapped up in its own local affairs and subject to no control from outside, would not promote the common interests of the whole people. [Sidenote: Difference between the theory and the practice of home rule.] Municipal home rule means in practice, therefore, that cities shall be free to frame their own charters and to determine for themselves their form of municipal government provided they do not infringe upon the general laws of the state or detract from the authority of the state officials. This is a very broad limitation and leaves the city a comparatively narrow field of self-determination. Nevertheless, in spite of this limitation the home rule system has substantial advantages. It relieves the legislature from having to do with a multitude of local matters at every session; it helps to separate municipal from state politics; and it encourages the people of the city to take an active interest in the making of their own charters.[71] [Sidenote: The older form of municipal organization.]