Chapter 1 • International Human Rights Law and the Role of the Legal Professions: A General Introduction v Secondly, according to the dualist theory, municipal law and international law are different legal systems. Municipal law is supreme, and for municipal judges to be competent to apply international treaty rules, for instance, these have to be specifically adopted or transposed into domestic law. It follows that a human rights treaty ratified by the State concerned cannot in principle be invoked by local judges unless the treaty is incorporated into municipal law, a process which normally requires an Act of Parliament. However, these theories have been criticized for not reflecting the conduct of national and international organs, and they are gradually losing ground. For legal practitioners it is therefore more important to emphasize practice rather than theory.54 Changes in the role and in domestic perception and understanding of international law in general, and of international human rights law in particular, have led to an increased use of such law in domestic courts. One of the purposes of this Manual is therefore to prepare judges, prosecutors and lawyers to adapt and contribute to these fundamental changes. The following is a list of some of the principal means through which international human rights norms can be contained in municipal law or otherwise applied by domestic courts and other competent authorities: v Constitutions: Many constitutions actually contain numerous human rights provisions, which may follow the text of, for instance, the Universal Declaration of Human Rights, the International Covenant on Civil and Political Rights or the regional human rights conventions. The use of such common language enables judges, prosecutors and lawyers to draw upon the jurisprudence of, in particular, international courts and other monitoring organs in interpreting the meaning of their own constitutional or other provisions; v Other national legislation: Many States adopt specific legislation either to clarify or elaborate on their constitutional provisions, or in order to adapt their domestic laws to their international legal obligations. When transforming international law into municipal law, the same legal terms are often used, thus allowing the legal professions to draw inspiration from international jurisprudence or the jurisprudence of other States; v Incorporation: It is also common for States to incorporate international human rights treaties into their domestic law by enacting a national law. This is for instance the case with the European Convention on Human Rights in the United Kingdom, where that Convention was incorporated into British law by virtue of the Human Rights Act 1998, which entered into force on 2 October 2000; v Automatic applicability: In some States treaties take precedence over domestic law and are thus automatically applicable in domestic courts as soon as they have been ratified by the State concerned; v Interpretation of common law: In interpreting common-law principles, judges may be governed by international human rights law and international jurisprudence interpreting that law; 54 As to monism and dualism Higgins states that of “course, whichever view you take, there is still the problem of which system prevails when there is a clash between the two”; and that “in the real world the answer often depends upon the tribunal answering it (whether it is a tribunal of international or domestic law) and upon the question asked”; in her view different “courts do address that problem differently”, see Rosalyn Higgins, Problems and Process: International Law and How We Use It (Oxford, Clarendon Press, 1994), p. 205. Human Rights in the Administration of Justice: A Manual on Human Rights for Judges, Prosecutors and Lawyers 21