The Rule of Law is a concept often used by politicians, though it corresponds to different legal understandings and even terminology (Etat de droit in French, or Rechtstaat in German). I shall here use a closer expression in English to what would be the literal translation from the continental phrase, State of Law, rather than Rule of Law.
Carl Schmitt, the German classic of political thought despite his personal alignment in the 1930s, treated the issue in his famous “Theory of the Constitution” (Verfassungslehre, 1928), published before the Nazis seized power.
The first time he refers to the term is when dealing with the different ideal types of Constitution and, particularly, with that of the bourgeois State:
An organisation of the State from a critical and negative point of view with regards to State power -citizen protection against State power abuse-. Means and methods for State control are organised more than the State itself.
This idea of the State of Law would rather correspond to the principles of conservative thought. The citizen needs to be protected against the State, which should therefore be as small as possible, in order to prevent abuse.
In order to implement such protection, Schmitt gives a preliminary clue:
To limit in a normative series all the activity of the State through competences, limited in principle and rigorously circumscribed.
Again, this would sound familiar to a conservative perception. A public authority can only act if and when it has a recognised competence.
In the bourgeois State of Law, the limitation is also materialized through the division of powers. And the recognition of fundamental rights reflects how the citizen can act vis-a-vis the state in a positive manner, the principle of his political participation, beyond the pure negative conception of state limitation.
But these four elements do not preclude the form of government, which in principle is irrelevant for the State of Law. This can exist in a Monarchy, an Aristocracy, a Democracy, or a status mixtus.
This could perhaps sound less aligned to what has become a predominant current conservative trend, where Democracy is a pillar, or even the pillar, of the State of Law.
Schmitt does delve into the problem of the relationship between the bourgeois State of Law and the different forms of government.
For example, if one introduces the principles of the State of Law to Monarchy, this becomes a constitutional Monarchy. The clue, once more, is that the State, in this case represented by the Monarch, is not absolute, but limited.
Though, on the other side, Democracy could also be absolute and not respectful of the same limitation against the abuse of power, fundamental rights or division of powers if, for example, it punishes an innocent, or it breaches freedom of thought, or freedom of conscience, or it attacks private property.
This is why Schmitt corrects a preliminary view where the form of government is completely independent from the bourgeois State of Law to speak of an influence of the latter on the former so that both create a mixed Constitution, be that a moderate/constitutional Monarchy or a moderate/constitutional Democracy.
Our author speaks of a second mixture, this time derived from the division of powers, in the State of Law. This would rather be a status mixtus than a Monarchy, an Aristocracy, or a Democracy, because in the implementation of the division of powers in different nations, one can always see the monarchical principle, the aristocratic principle and the democratic principle.
Already the great classical authors Aristotle, Polybius and St. Thomas Aquinas praised the status mixtus in both Ancient Greece and Rome as well as the Middle Ages, since both a Monarchy, an Aristocracy or a Democracy can degenerate, and hence an adequate mixture of the three forms an optimal Constitution.
Image source: Wikipedia.