List of branches of law

1. ↑ constitutional law. Constitutions are fundamental legal documents that define the structure, rights and governance of a state. Emerging from Enlightenment ideas and historical practices, they can be written or unwritten, with most modern constitutions being formal documents created by representative assemblies. Academics such as Kelsen see constitutions as the highest legal norm, establishing the basis for the laws of the state and protecting human dignity. Different perspectives - legal, political and sociological - offer varying interpretations of constitutional principles. Constitutional norms address rights, political participation and state organisation, and also reflect social forces and political decisions. Examples such as the British, Brazilian, Portuguese, Angolan and Timorese constitutions demonstrate diverse approaches to constitutional design, from traditional unwritten systems to comprehensive written documents. The central purpose remains consistent: to organise state power, protect individual rights and provide a framework for democratic governance.

2. ↑ private law. The distinction between public and private law originates in Roman legal traditions, initially differentiating between state interests and individual utility. This classification is fundamental to legal education and reflects the separation between the public and private spheres. Modern legal scholarship challenges clear demarcation, highlighting the complexity of legal relationships and the emergence of hybrid legal domains. The evolution of constitutional thinking has significantly impacted this distinction, introducing concepts of fundamental rights and judicial review. The 20th century witnessed a transformation in private law through publicisation and constitutionalisation, emphasising human dignity over property rights. This shift represents a movement to place the human person at the centre of legal interpretation, challenging traditional hierarchical legal structures and recognising the interconnectedness of public and private legal domains.

3. ↑ public law. The division between public and private law derives from Roman legal traditions, particularly Ulpiano's distinction between jus publicum and jus privatum. This classification separates legal rules on the basis of interests (public vs. private), types of legal relations (coordination vs. imposition) and forms of interaction (imperative vs. autonomy). Public law covers international, constitutional, administrative, criminal, financial and tax law, while private law has weakened as the state increasingly intervenes in legal domains. Criticisms of this division include a lack of precision, oversimplification of legal complexities and insufficient differentiation between individual and collective interests. Modern interpretations see the constitution as the foundation of all domestic law, blurring traditional boundaries and suggesting that all law potentially becomes public. The separation reflects the evolving relationship between state and society, highlighting the dynamic nature of legal categorisation.

4. ↑ legal order. Legal order represents the sociological dimension of law, examining legal systems from an external power perspective. Academics such as Weber and Marx explore this concept through societal power dynamics. Order, as defined by Weber, guides human action through established maxims, with law distinguished by its coercive enforcement mechanism. Kelsen emphasises that the legal order is fundamentally a system of norms validated by a foundational norm, with coercion as its defining characteristic. The legal order determines the conditions and agents of enforcement, maintaining a monopoly on physical force within a community. The international legal order remains controversial, characterised by decentralised mechanisms where states respond to violations through reprisals and conflict, lacking centralised normative institutions. The system operates through complex interactions between societal norms, power structures and regulatory frameworks, with coercion serving as a critical mechanism for maintaining social conformity.

5. ↑ regulations. Regulations are normative acts issued by the executive branch, characterised by abstraction, generality and imperativeness. They serve to detail higher normative acts and are mainly limited by constitutional and legal frameworks. Classifications include regulatory, delegated, autonomous and independent types, ranging in scope from internal administrative effects to external general effects. They can be spontaneous or provoked, and cover various levels of governmental competence, including federal, state, municipal and territorial. Autonomous regulations directly explain the Constitution and constitute primary normative acts, while independent regulations also interpret constitutional provisions. The principle of legality prevails in contemporary constitutional systems, ensuring that regulations operate within defined legal limits. Academic work by authors such as Francisco, Leal and Velloso has contributed to understanding the complex nature and function of regulatory mechanisms.

6. ↑ tax law. Tax law covers the legal framework governing taxation, focusing on principles, sources and types of tax. It explores the historical development of taxation systems, particularly in Brazil, tracing the evolution from feudal contributions to modern constitutional frameworks. Fundamental principles include legality, equality, non-retroactivity and taxpayer guarantees. The Brazilian tax system has undergone significant transformations, with important milestones in 1934, 1978 and 1988, establishing clear regulatory structures for federal, state and municipal taxes. The system covers various types of taxes, including income, wealth, consumption, fees and special contributions. Despite its comprehensive nature, tax law faces challenges such as complex regulations, frequent legislative changes and compliance difficulties. The discipline balances the generation of government revenue with the protection of taxpayers' rights, reflecting the intricate relationship between the state's fiscal needs and individual economic freedoms.

7. ↑ society. A society is a group of individuals interacting to achieve common goals, sharing a fundamental principle of bonding. Characterised by networks of interconnected relationships, societies can be institutionalised or non-institutionalised, ranging from bands and tribes to complex state structures. Communities serve as intermediary groups between individuals and wider societal structures, encompassing family, professional and social networks. Anthropological perspectives emphasise the organisation of societies based on subsistence, technology and communication, challenging previous hierarchical notions. Social norms and institutions play crucial roles in maintaining group cohesion, with mechanisms such as generosity, status recognition and shared rituals. The evolution of societies reflects changing dynamics of cooperation, specialisation and adaptation, demonstrating how human groups organise themselves to survive and thrive in different cultural and environmental contexts.

8. ↑ law. Law is a complex system of rules that regulate human behaviour through rights and duties, shaped by various social and cultural influences. Rooted in Latin and Sanskrit origins, it encompasses various legal families such as civil law and common law. The field largely distinguishes between public and private law, addressing corporate and individual interests respectively. Its foundations date back to archaic societies, with early codifications such as the Code of Ur-Namu and the Code of Hammurabi. Roman law significantly advanced legal systems, separating law from religion and morality, and developing sophisticated legal concepts. Modern law comes from multiple sources, including state legislation, international treaties and individual contracts. Courts and tribunals apply legal norms through interpretation guided by doctrine, custom and judicial precedent, reflecting the dynamic and adaptive nature of law.

9. ↑ system. A system is a complex arrangement of interconnected components working towards a common goal. Characterised by functional integration and synergy, systems can be physical or conceptual, ranging from biological organisms to organisational structures. Biological systems follow a hierarchical organisation from atomic to cosmic levels, while information systems in computer science focus on algorithmic processes. Systems interact dynamically with their environment through inputs and outputs, maintaining homeostasis through continuous communication between elements. Different types of systems exist across disciplines, including human biological systems such as digestive and nervous systems, and social systems such as economic and legal structures. The core principle underlying all systems is the interdependence of the components, where changes in one part can significantly influence the functionality and performance of the entire system.