The constitution, in law, is the fundamental regulatory act that defines the nature, form, structure, activity and fundamental rules of an organization or the top of the hierarchy of sources that defines the legal system of a State of law.
The term indicates the fundamental law of a State, or the top in the hierarchy of sources of law, while for the fundamental act of other bodies, public or private, the denomination of statute is usually adopted. From a sociological point of view, it is the result of centuries of European and Western historical-political evolution, which later established itself worldwide with multiple contaminations. Constitutional law derives from it.
Origin and meaning of the term
The term derives from the Latin constitutio, which referred to a law of particular importance usually issued by the emperor, and in this particular meaning it is still used in canon law to indicate relevant decisions taken by the pope such as, above all, the apostolic constitution establishing the regime to be followed during the period of vacancy and for the election, in the subsequent conclave, of the new bishop of Rome.
In any case, the term is rich in meanings, both descriptive and axiological. From a descriptive point of view, one can generally, and with a certain approximation, affirm that the constitution is the fundamental law of a legal system, the main, or superprimary, source from which the legality of all other sources derives. From an axiological point of view, however, widespread above all by the Enlightenment and the French Revolution, the term constitution indicates a specific fundamental law, and in particular the fundamental law that founds a system of separation of powers.
The first studies on the constitution date back to the Enlightenment period and quickly became the subject of a political declination of the liberal principle called constitutionalism, whose history spanned all the following two centuries: "limits to power and democratization constitute (...) the two elements that characterize contemporary constitutionalism both as regards the (...) relations between the individual and authority (form of state), and as regards the relations between the supreme constitutional bodies in relation to the function of political direction (form of government) and the transition from the so-called parliamentary legislative state to the constitutional state.
The constitutional state of law identifies - as is well known - a system where constitutional values are supreme, not vulnerable to changing parliamentary majorities, even if they can be interpreted in a diversified way. Its introduction constituted for the European context a progressive abandonment of the theory of the traditional supremacy of the legislative body (understood in a strict or complex sense) and the construction of a system where the fundamental rights of individuals and the relationships between constitutional bodies are subject to jurisdictional limits and guarantees ".
A real constitution (strictly speaking) is a body of fundamental laws produced by the sovereignty of the people, usually through a constituent assembly. If the constitution is the result of a transfer of authority by a monarch, we usually speak of a "constitutional statute" (eg Albertine statute of 1848) or a "constitutional charter". The statute is an ottriate constitution (that is, granted by a sovereign, up to that moment absolute).
Both for these historical origins and for the role exercised in the institutional life of modern states, the Constitution fulfills the function of "legal limitation of politics".
The majority of states have a written Constitution at the basis of their legal system (such as that of Italy and that of the United States of America