Mutamento costituzionale e dogmatica giuridica

Do constitutional changes take place only through legislative amendment of the Constitution or judicial overruling? Or Constitutions change even in contact with facts? Is there a normative power of the factual, or the legal system is exclusively made by formal acts? The paper tries to provide an answer to these questions, and proposes the concept of ‘constitutional change’ (Verfassungswandel) elaborated by German scholars by the end of XIX Century as a tool to focus on otherwise invisible alterations of the constitutional document