The analytical and historical distinction between public and private law has emerged predominantly in the legal systems of
continental Europe. As a result, German-language legal literature has produced extensive discussion on the precise nature of the distinction between public law and private law. Several theories have evolved, which are neither exhaustive nor mutually exclusive or separate. The interest theory of public law emerges from the work of
Roman jurist
Ulpian, who stated "
Publicum ius est, quod ad statum rei Romanae spectat, privatum quod ad singulorum utilitatem. (Public law is that which concerns the Roman state, and private law is concerned with the interests of citizens.)
Charles-Louis Montesquieu elaborates upon this theory in
The Spirit of the Laws, published during the 18th century, wherein Montesquieu establishes a distinction between international (right of nations), public (political right), and private (civil right) law according to various actors' interests and rights. There, he writes: "Considered as inhabitants of a planet so large that different peoples are necessary, they have laws bearing on the relation that these peoples have with one another, and this is the . Considered as living in a society that must be maintained, they have laws concerning the relation between those who govern and those who are governed, and this is the . Further, they have laws concerning the relation that all citizens have with one another, and this is the ." Criticisms of interest theory include the difficulty of establishing a clear distinction between private and public interest, if such a distinction exists, and of categorizing laws accordingly. The subjection theory explains the distinction by emphasizing the subordination of private persons to the state. Public law is supposed to govern this relationship, whereas private law is considered to govern relationships in which the parties meet on a level playing field. However, some areas commonly considered private law also imply subordination, such as
employment law. Moreover, legal proceedings wherein the State is a party may undermine the totality of the State's authority, and the degree to which private persons are subordinate to the State if a Court finds in favor of a non-state party (see
Carpenter v. United States, for example). The subject theory concerns the position of the subject of law within the legal relationship in question. If it finds itself in a particular situation as a public person (due to membership in some public body, such as a state or a municipality), public law applies; otherwise, it is private law. A combination of the subjection theory and the subject theory arguably provides a workable distinction. Under this approach, a field of law is considered public law where one actor is a public authority endowed with the power to act unilaterally (
imperium), and this actor uses that
imperium in the particular relationship. In other words, it all depends on whether the public authority is acting as a public or private entity, for example, when ordering office supplies. This latest theory considers public law a special instance. There are areas of law that do not seem to fit into either public or private law, such as
employment law – parts of it look like private law (the employment contract) while other parts look like public law (the activities of an employment inspectorate when investigating workplace safety). The distinction between public and private law bears on the delineation of the competencies of different courts and administrative bodies. Under the
Austrian constitution, for example, private law is among the exclusive competencies of federal legislation, whereas public law is partly a matter of
state legislation. ==See also==