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The concept of the Rechtsstaat goes back to the early 19th century, when German scholars - strongly impressed by the reason-based philosophy of Immanuel Kant - formulated a rule of law program in order to rationalize political rule and to institutionalize liberal claims against absolutist state-conceptions ("gute policey") (see Böckenförde 1969: 144-150; Martini 2009: 308). The state should be shaped and framed, bound and limited by the law in three ways: (1) the state administration should be based on law ("Gesetzmäßigkeit der Verwaltung"), (2) regulation by formal laws law should especially be required especially for all state action relevant for individual freedom and property rights rights ("Gesetzesvorbehalt"), and (3) all administrative actions should be subject to judicial review. All three of these set formal requirements without providing specific substantive normative standards. This lead to an understanding of Rechtsstaatlichkeit as a formal provision. Finally, around 1900, judicial positivism as the leading paradigm in constitutional theory made for the complete exclusion of substantive and, therefore, politically contested criteria from the concept of Rechtsstaatlichkeit (see Böckenförde 1969: 155). In 1928, Hans Kelsen in his "Pure Theory of Law" ("Reine Rechtslehre") radically affirmed the identity of the state and the law. The state was nothing but Rechtsstaat in a formal sense of the term.
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