The term "police power" is used to designate that most important function of securing the largest practicable measure of wellbeing to those who live together in the social organization. This is indeed the ultimate object of government. No very specific or complete definition or description of this power can be framed, nor has it been often attempted. Perhaps an enumeration of some of the most important subjects which indisputably fall within it will give a better idea of its scope and nature than any technical definition.

(1) The legislature may provide for the acquisition, use, and control of property for the public benefit, such as for public buildings, charitable and educational purposes, highways, parks, and public grounds. Such property is acquired by the exercise of the power of eminent domain; but legislation in reference to the exercise of that power, and in reference to control and enjoyment by the public, is within the scope of the police power. There are also public rights in navigable streams and inland lakes and the seas, bays, and other waters, so far as they are within the jurisdiction of the state, which the state may properly regulate. It may also make regulations for the preservation of fish and game on the theory that they are a species of public property in which the people of the state have a common interest.

(2) Legislation as to the public school system and institutions of higher education, at least so far as they are provided at the public expense, is within the scope of the police power.

(3) Some kinds of property and some callings are so far of a public nature that the state may regulate them to a greater extent than it may regulate property and callings not public in their nature; and such regulations are made in the exercise of the police power. For instance, the legislature may regulate the rates to be charged by railroads and express companies and by those operating public elevators or warehouses, and may control the business of hotel keepers and others furnishing places of public entertainment. The exercise of the police power in the regulation of rates of charge for public services is in recent years very largely extended. Corporations such as gas and electric light, water, street car and other companies to which are given the privilege of using the streets of a city for the advantage of the public may be controlled as to their rates and charges, even though no such reservation has been expressly made by constitutional or statutory provision. The charters of such companies, although they are regarded as contracts, do not exempt them from such regulation. (See below, § 269.)

(4) In the furtherance of the public welfare the legislature may control the use of property which is strictly private in its nature, and the business and conduct of individuals, on the general principle that each individual may be restricted in his own actions and in his own property so as not to interfere with the enjoyment of like privileges of others. Thus the owner of property may be prevented from using it for purposes obnoxious to his neighbors, that is, he may be prevented from maintaining a nuisance; the heights of buildings in cities may be restricted; fire limits in cities may be fixed, within which buildings of wood or other inflammable material may not be constructed; the storage and sale of explosives or extremely inflammable materials may be regulated; to some extent limitations may be placed on hours of labor, especially for the preservation of the health of those engaged, or for the protection of the weak, as women and children (and see below, § 261); the sale of intoxicating liquors and drugs may be regulated and controlled; a large measure of power may be exercised with reference to the protection of public health; immorality may be suppressed; business, such as the carrying on of lotteries, which is deemed contrary to public policy, may be forbidden; the rates of interest on loans of money may be limited. (5) Finally, without continuing further the enumeration, which might be extended to cover a long list of subjects, the destruction of property by reason of some controlling public necessity may be authorized.