Public and Private Law: Concepts, Divisions, and Historical Evolution

Public and Private Law: Concepts and Divisions

Law is traditionally divided into public law and private law. Public law regulates relations between the State and the public, while private law governs relations between private individuals.

Historical Origins

The distinction originates in Roman law. Ulpian preferentially defined public law as that which concerns the condition of the Roman state (quod ad statum rei Romanae spectat), and private law as that which concerns the utility of individuals. Livy regarded the Twelve Tables as the source of all public and private law (privatum publicumque ius ex XII tabulis).

Middle Ages and the Modern Era

During the Middle Ages, notions of power, domain, policy and equity were often confused. The Renaissance brought new divisions of law, and Domat later divided law into gentes, public law, private law, and particular laws concerning commerce and public finance.

The Contemporary Period

Conflict between liberal and interventionist tendencies marked the contemporary age. The Liberal Revolution vindicated the innate rights of the individual against the State. Public law was reduced to a service of the State, while private law came to constitute the system and foundation of individual freedoms and rights. Later, with the growth of legislative activity, the boundaries between the two have tended to blur.

Theories of Distinction

Several theories have attempted to explain the division:

• Dualist theories: focus on the subject of the relationship.
• Subjectivist theories: focus on the object of the relationship.
• Pluralist theories: focus on the form of the relationship.

Branches of Public Law

Constitutional Law

Constitutional law is the fundamental branch of public law. It regulates the principles of government and the organisation of the State. Its origins trace back to the Greek polis and the Roman city-state. J. Bodin defined the State in relation to three elements: territory, population, and sovereignty.

The separation of powers, originally formulated by Montesquieu in the eighteenth century, divides State power into three branches:

• Legislative: responsible for drafting laws through parliaments or cortes.
• Executive: applies laws, directs policy, and manages public administration.
• Judiciary: applies and interprets laws through independent and impartial courts.

The three powers exercise reciprocal control over one another.

The Spanish Constitution

Article 1.1 of the Spanish Constitution of 1978 establishes Spain as a democratic and social State that advocates liberty, justice, equality and political pluralism as supreme values of its legal order. Article 1.2 states that national sovereignty resides in the Spanish people, from whom the powers of the State emanate.

Under Article 66 and following, the Cortes Generales represent the Spanish people and are formed by the Congress of Deputies and the Senate. The Cortes exercise legislative power, approve the budget, and control government action.

Administrative Law

Administrative law regulates the organisation and activity of public administration. Article 97 of the Constitution assigns the Government the function of directing the domestic and foreign policy of the nation and of exercising administrative power. Public administration has legal personality and operates under the principle that the interest of the general public prevails over that of the individual.

Citizens are guaranteed several protections, including:

• Economic guarantees: the right to compensation for expropriation at fair price.
• Legal guarantees: the right to be heard in administrative proceedings and access to administrative and contentious-administrative appeals.

The main administrative remedies are the recurso de reposición (before the same body), the recurso de alzada (before the superior hierarchical authority), and the recurso extraordinario de revisión.

Financial, Tax, and Fiscal Law

Financial law regulates public revenue and expenditure. Tax law governs the imposition and collection of taxes and the rights and duties of taxpayers. Fiscal law establishes the State's tax obligations and procedures.

Criminal Law

Criminal law defines criminal offences and attaches penalties and security measures to them. Classical liberal thinkers defended two core principles: the primacy of law, and moderation of penalties. Key principles include:

• No penalty may be imposed unless provided for by law (nulla poena sine lege).
• Criminal laws may not be applied retroactively.
• No act may be considered a crime unless previously defined as such by law (nullum crimen sine lege).
• Penal provisions must be interpreted restrictively.

Penalties are classified as custodial, restrictive of liberty, restrictive of rights, and pecuniary.

Procedural Law

Procedural law regulates the sequence of legally regulated acts and the bodies that intervene in the administration of justice, from the exercise of action to the final judgment. In Roman law, actio and iurisdictio formed the basis of this system. Jurisdiction, understood as the power to declare law (iuris dictio), refers to judicial activity aimed at resolving disputes through the application of law.

Article 117.1 of the Constitution states that justice emanates from the people and is administered on their behalf by judges and magistrates who are independent, irremovable, responsible, and subject only to the rule of law. Article 117.5 establishes the principle of unity of jurisdiction as the basis of the organisation and functioning of the courts.

The main jurisdictions include:

• Civil jurisdiction: private disputes, regulated by the Civil Procedure Act (Ley 1/2000).
• Criminal jurisdiction: criminal cases, regulated by the Criminal Procedure Act (Ley de Enjuiciamiento Criminal).
• Contentious-administrative jurisdiction: disputes involving the administration.
• Labour jurisdiction: employment-related disputes.
• Military jurisdiction: offences committed by military personnel.
• Canonical jurisdiction: ecclesiastical matters, including matrimonial cases of Catholics, under the Code of Canon Law of 1983.

International Public Law

International public law regulates relations between States and international organisations, whose nature is supranational. In Rome, it was known as ius gentium, the law of nations. In the Christian world, the doctrine of the ius gentium was used to justify just or unjust wars. The existence of binding international law among nations developed with modern conquest and was consolidated through custom, treaties, and arbitration.

Conflicts between States are resolved through two main mechanisms:

• Non-judicial: diplomatic relations and the framework of international organisations.
• Judicial: intervention of international courts and tribunals.

The United Nations was established by the Charter of San Francisco in 1945.

Branches of Private Law

Civil Law

Civil law is the historical core of private law and regulates the relations of citizens. In Rome, ius civile was formed by the interpretation of jurists and was opposed to ius gentium and natural law, as Gaius explained. Each nation establishes its own civil law.

Civil law governs the legal circumstances of a person from birth to death. Its content is traditionally divided into three parts following Gaius: persons, things, and actions. Savigny later divided it into five parts: general part, property rights, obligations, family, and succession.

The Spanish Civil Code of 1889, promulgated during the regency of Maria Cristina, contains 1,976 articles divided into a Preliminary Title and four Books: persons, property and its modifications, methods of acquiring ownership, and obligations and contracts. Some regions have their own civil regime, known as derecho foral, codified in the Compilaciones forales of 1959 to 1973. Article 149.1 of the Constitution reserves to the State exclusive competence over civil legislation, without prejudice to the conservation, modification, and development of foral civil law by the Autonomous Communities.

Commercial Law

Commercial law emerged as an independent discipline of private law in the nineteenth century, although its precedents can be found in medieval guilds and corporations of merchants. In Rome, there were also associations of traders and shippers. The notion of commercial law has evolved from a subjective conception, centred on the merchant, to an objective conception, centred on commercial acts and the business enterprise.

The structure of commercial law rests on three concepts:

• The entrepreneur: the holder of the business, subject to commercial rights and obligations.
• Business activity: organised and professional economic activity aimed at producing or exchanging goods and services for the market.
• The commercial establishment: the set of assets used to carry out the business activity.

The legal regime of companies is of particular importance, especially the public limited company (sociedad anónima), a capitalist company with limited liability. Other companies include the general partnership (sociedad colectiva), the limited partnership (sociedad comanditaria), and the limited liability company (sociedad de responsabilidad limitada).

Conclusion

The distinction between public and private law remains central to legal thinking, although the boundary between them has become increasingly blurred. Public law organises the State and its relation to citizens, while private law regulates the autonomy and rights of individuals. Both branches continue to evolve in response to social, economic, and political change.