In the same general manner, we may summarize the principal functions of the state[187] as follows: the state has the right and power to organize and control the economic system, comprehending in that term the production and distribution of all social wealth, wherever private enterprise is dangerous to the social well-being, or is inefficient; the defense of the community from invasion, from fire, flood, famine, or disease; the relations with other states, such as trade agreements, boundary treaties, and the like; the maintenance of order, including the juridical and police systems in all their branches; and public education in all its departments. It will be found that these five functions include all the services which the state may properly undertake, and that not one of them can safely be intrusted to private enterprise. On the other hand, it is not at all necessary to assume that the state must have an _absolute monopoly_ of any one of these groups of functions in the social organism. It would not be necessary, for example, for the state to prohibit its citizens from entering into voluntary relations with the citizens of other countries for the promotion of international friendship, for trade reciprocity, and so on. Likewise, the juridical functions being in the hands of the state would not prevent voluntary arbitration; or the state guardianship of the public health prevent voluntary associations of citizens from taking measures to advance the health of their communities. On the contrary, all such efforts would be advantageous to the state. Our study becomes, therefore, a study of social physiology.