Hans Kelsen

Hans Kelsen was an Austrian jurist and legal philosopher who developed the Pure Theory of Law and influential arguments for constitutional review by specialized courts.

Pure Theory of Law: A theory that explains law as a system of valid norms, studied separately from morality, politics, and other social facts. Kelsen’s best-known project, developed across several works and revised throughout his career.
Constitutional review: The examination of laws or government actions for conformity with a constitution. Kelsen argued that a specialized court could enforce constitutional limits by reviewing legislation.
Adolf Merkl: An Austrian legal theorist associated with the Vienna School of legal theory and the hierarchical structure of legal norms. Merkl developed the ‘dynamic’ account of legal hierarchy alongside Kelsen’s broader project.
Natural law: The view that law is connected to moral principles or standards that exist independently of enacted rules. Kelsen rejected using moral validity as the test for whether a norm belongs to a legal system.
Grundnorm: The presupposed basic norm that allows a legal system’s norms to be understood as valid within one hierarchy. It anchors Kelsen’s account of legal validity without deriving law from moral or political authority.
Constitutional court: A court whose central function is interpreting and enforcing a constitution. Kelsen helped shape the model of a separate court empowered to invalidate unconstitutional statutes.
Carl Schmitt: A German jurist and political theorist known for theories of sovereignty, dictatorship, and the political nature of law. Schmitt challenged Kelsen’s preference for judicial guardianship of the constitution.
Legal realism: An approach that emphasizes how legal institutions and officials actually behave when explaining law. Realists focus on social practice where Kelsen’s theory isolates the normative structure of law.
Legal positivism: The jurisprudential view that a law’s existence and content depend on social facts, not necessarily on its moral merit. Kelsen’s theory is a distinctive form of positivism, though it gives legal norms a highly systematic structure.
Austrian Constitutional Court: Austria’s constitutional court, established under the 1920 constitution to review the constitutionality of laws. Kelsen helped draft the 1920 Austrian Constitution and served on the court it established.

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