The concept in its Danish variant (Retsstat), as illustrated in Justice Party propaganda, 1939

Rechtsstaat is a doctrine in continental European legal thinking, originating in German jurisprudence. It can be translated into English as "rule of law", alternatively "legal state", "state of law", "state of justice", "state of rights", or "state based on justice and integrity".[1]

A Rechtsstaat is a "constitutional state" in which the exercise of governmental power is constrained by the law.[2] It is closely related to "constitutionalism" while is often tied to the Anglo-American concept of the rule of law, but differs from it in that it also emphasizes what is just (i.e., a concept of moral rightness based on ethics, rationality, law, natural law, religion, or equity). Thus it is the opposite of Obrigkeitsstaat or Nichtrechtsstaat (a state based on the arbitrary use of power),[3] and of Unrechtsstaat (a non-Rechtsstaat with the capacity to become one after a period of historical development).[4]

In a Rechtsstaat, the power of the state is limited in order to protect citizens from the arbitrary exercise of authority. The citizens share legally based civil liberties and can use the courts.

Immanuel Kant

German writers usually place the theories of German philosopher Immanuel Kant (1724–1804) at the beginning of their accounts of the movement toward the Rechtsstaat.[5] Kant did not use the word Rechtsstaat, but contrasted an existing state (Staat) with an ideal, constitutional state (Republik).[6] His approach is based on the supremacy of a country's written constitution. This supremacy must create guarantees for implementation of his central idea: a permanent peaceful life as a basic condition for the happiness of its people and their prosperity. Kant proposed that this happiness be guaranteed by a moral constitution agreed on by the people and thus, under it, by moral government.[7]

Kant's political teaching may be summarized in a phrase: republican government and international organization. In more characteristically Kantian terms, it is doctrine of the state based upon the law (Rechtsstaat) and of eternal peace. Indeed, in each of these formulations, both terms express the same idea: that of legal constitution or of 'peace through law.' ... Taking simply by itself, Kant's political philosophy, being essentially a legal doctrine, rejects by definition the opposition between moral education and the play of passions as alternate foundations for social life. The state is defined as the union of men under law. The state rightly so called is constituted by laws which are necessary a priori because they flow from the very concept of law. A regime can be judged by no other criteria nor be assigned any other functions, than those proper to the lawful order as such."[8]

The actual expression Rechtsstaat appears to have been introduced by Carl Theodor Welcker in 1813,[9][10] but it was popularised by Robert von Mohl's book Die deutsche Polizeiwissenschaft nach den Grundsätzen des Rechtsstaates ("German Policy Science according to the Principles of the Constitutional State"; 1832–33). Von Mohl contrasted government through policy with government, in a Kantian spirit, under general rules.[11]