Niklas Luhmann's The Law of Society (1993) is a central component of his social theory. Luhmann analyzes law not normatively, but functionally and systems-theoretically: as an operationally closed, autopoietic system within functionally differentiated modern society. The volume is divided into twelve chapters that systematically address central questions of legal sociology, legal theory, and systems theory:

1. Legal Theoretical Starting Point
Luhmann distances himself from classical legal sociological approaches and embeds law systems-theoretically into his theory of society. He does not ask what influence society has on law, but rather how law is possible within society.

2. The Operational Closure of the Legal System
The legal system is described as operationally closed, i.e., it reproduces itself exclusively through legal communication. Its code is lawful/unlawful, and its unity arises from this communication, not from external factors.

3. The Function of Law
Law stabilizes normative expectations under conditions of social complexity. It enables certainty of action in social relationships, especially where personal relationships of trust are no longer sufficient.

4. Coding and Programming
Luhmann distinguishes between the binary code of lawful/unlawful and programs that concretize this code (e.g., laws). Programs are contingent conditions that determine the application of the code.

5. The Contingency Formula of Justice
Justice serves as a symbolic formula for the legitimization of law, although it is itself indeterminable. It functions as a reflection figure for the contingency of legal decisions.

6. Evolution of Law
Law develops historically with society. In modern societies, positive law replaces traditional, religiously, or morally legitimated norms. This change is evolutionary and cannot be planned.

7. The Position of Courts in the Legal System
Courts are central decision-making bodies in the legal system. They must process the contingency of legal decisions by producing comprehensible judgments that stabilize and advance the system.

8. Legal Argumentation
Legal argumentation is not a rational process of proof, but a form of communication that plausibly creates connectivity. It utilizes system-specific distinctions and programmatic logics.

9. Politics and Law
Politics and law are two separate functional systems. They are linked through constitutions or laws, but their logics (power vs. right/wrong) remain distinct. Political decisions cannot directly control law.

10. Structural Couplings
Structural couplings exist between law and other systems (e.g., politics, economics) that enable communication without sacrificing the systems' autonomy. Such couplings are necessary to coordinate systemic complexity.

11. The Self-Description of the Legal System
Law describes itself using certain semantic patterns (e.g., justice, constitutional state). These self-descriptions are not "true," but functional—they stabilize expectations and legitimize the system.

12. Society and Its Law
The concluding chapter reflects on the relationship between society and law. Law is a functional system of society, fulfills a social function, and enacts society through its own mode of operation. Society is both the environment and the potential space of law.

Conclusion
Luhmann's The Law of Society demonstrates that law cannot be reduced to morality, justice, or political control. It is an independent, autopoietic communication system that operates through the code of right/wrong and is only possible in this form in functionally differentiated societies. Luhmann thus provides a fundamental counter-model to normative legal philosophy.