The Rechtsstaat in a Substantive and a Formal Sense: Revisiting the Theory Development of the 1830s and 1840s

The concept of “Rechtsstaat” developed in the 1830s and 1840s in the German constitutional discussion. Robert von Mohl developed the concept in a substantive sense and Friedrich Julius Stahl then developed it in a formal sense. In this article, the theories of the two scholars are first explained and analysed in the context of their understandings of the State and the law as well as the philosophical underpinnings of their constitutional theories. The Rechtsstaat in a substantive sense is closely related to a State where the law is pre-existing and individuals have formed the State through a social contract. The Rechtsstaat in a formal sense is closely related to a State which is defined by sovereignty and where the State and the law are indissociable.

Further on, the substantive and formal senses of the concept of Rechtsstaat are examined in the context of the discussion about how to define that concept and about whether “Rechtsstaat” and “rule of law” have the same meaning. This is a topic of current interest, given the recent common definition of those concepts at the EU level.