Bearing in mind the difference between the powers of a state government which are general in their scope, and those of the federal government, which has only the enumerated powers conferred upon it by the federal constitution and those which are implied therefrom (see above, § 17) it is apparent that the general powers of legislation are vested in the legislatures of the states, while Congress has legislative authority only as to limited classes of subjects. It will be useful, therefore, to consider first the scope of state legislation. But it is not easy to be exhaustive in this respect, for the original state constitutions and some of a later period contain very few specifications as to the matters about which laws may be enacted.

The difficulties which bring before courts questions in regard to state legislation concern limitations on, rather than the extent of, the powers of the state governments. The general object of legislation is to provide for the public good and the health, good order, education, and morals of the people; and any statutes in furtherance of these purposes, and not in violation of limitations upon powers of the state government or its legislative department, will in general be valid. In determining the extent of legislative power we may properly have in mind the history of constitutional government in Great Britain and the United States, and especially the fact that in Great Britain Parliament is the legislative power, and we may safely say that those subjects with reference to which in the course of English history Parliament has been in the habit of dealing by way of legislation are within the scope of legislative power under our form of government, unless some constitutional restriction has been imposed. Out of this mass of potential powers, seldom enumerated in state constitutions, three classes of subjects for legislative power may be distinguished.

(1) All legislation relating to the carrying on of the operations of government, not only legislative, but also executive and judicial; for the general laws in accordance with which the functions of the judicial and executive departments are to be discharged must be provided by the legislative power. Thus legislation will provide for the election and appointment of judicial officers and apportion their duties to them, so far as their selection and duties are not directly controlled by the constitution. As to this kind of legislation, very little need be said by way of explanation or illustration, for the whole matter is left largely to the discretion of the legislatures.

(2) Legislation relating to the providing and expenditure of the revenues essential to the carrying on of the operations of the government; and this may be described in a general way as an exercise of the taxing power.

(3) Legislation relating to the control of the personal and property rights of those who are subject to the government, with a view to securing and promoting their general welfare; for this is the main object of government. Such legislation is an exercise of the so-called police power, which will be more fully explained in the next chapter.