Government bodies (central or local) can make decisions about the rights of persons.
However, as a consequence of the rule-of-law doctrine, authorities may only act within the law (secundum et intra legem).
For example, a citizen unhappy with a decision of an administrative authority can ask a court for judicial review.
[6] Drawing a line between public and private law largely fell out of favor in the ensuing millennium,[7] though, as Ernst Kantorowicz notes, Medieval jurists saw a concern with the Roman conception of the res publica inherent in the legal fiction of the king's two bodies.
Through the emergence of the nation-state and new theories of sovereignty, notions of a distinctly public realm began to crystalize.
[7] As such, legal scholars commenting on common law systems, such as England[11] and Canada,[12] have made this distinction as well.
[14] In Italy, for example, the development of public law was considered a project of state-building, following the ideas of Vittorio Emanuele Orlando.
Secondly, it sets out the form of government – how its different branches work, how they are elected or appointed, and the division of powers and responsibilities between them.
In some countries, however, such a supreme entrenched written document does not exist for historical and political reasons – the Constitution of the United Kingdom is an unwritten one.
This body of law regulates international trade, manufacturing, pollution, taxation, and the like.
It prescribes conduct perceived as threatening, harmful, or otherwise endangering to the property, health, safety, and welfare of people inclusive of one's self.
Until this point, taxes were considered gifts under the law, given to the State by a private donor – the taxpayer.
The analytical and historical distinction between public and private law has emerged predominantly in the legal systems of continental Europe.
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.
The subjection theory focuses on explaining the distinction by emphasizing the subordination of private persons to the state.
The distinction between public and private law has a bearing on the delineation between the competencies of different courts and administrative bodies.