The sovereign is expected to take care of his subjects and protect the composite elements of public order: religion, security and leisure. The plan of the city is its constitution. The physical structure and the structure of the rules are brought together in a single master plan adapted to the coexistence of the community in the public space, developed in accordance with the master plan. In fact, in ancient Greece, when a new colony was founded, the plan of the city went hand in hand with the constitution: both followed the master plan of the mother city (the metropolis). Despite the comparative interest in academic constitutional law (exemplified by the first international conference in 1900 and the founding of the Society of Comparative Legislation in Paris in 1869), modern comparative law (as a semi-autonomous discipline) was born from the efforts of experts in private law. This could be related to international commercial interests and also to the desire to export national civil codes. Such «imperialism» was certainly present in the promotion of the German Civil Code. Theories of comparative law reflected the considerations and concepts of private law, and constitutional law was often neglected in the comparative study of major legal systems. The low profile of constitutional law in comparative law may be due to difficulties in finding universal elements in constitutional law. Nevertheless, already in the interwar period, comparative constitutional law established itself as an independent scientific discipline.

The main concern of comparative law, as it appeared in the civil law tradition of the late nineteenth and early twentieth centuries, was to find the common legislative fund. This was the position of Capitant and Lambert in France and favoured the training of foreign lawyers in the national tradition in the name of comparative law. There is a similar trend in comparative constitutional law that emerges from the work of those whose main objective is to distil what is universal or common in all constitutional systems and traditions. As a result, comparative constitutional analysis is sometimes driven by a search for the universal on the basis of what can be observed empirically, or by agreement with the ideal arrangement (liberal, constitutionalist) by adapting various specific contexts in different cultural and historical circumstances. This search for the universal goes back to the tradition of comparative law illustrated by Anselm Feuerbach, the German scholar of the early nineteenth century, who is credited with the foundation of the discipline of comparative criminal law. The influence of comparative linguistics pursued by the liberal constitutionalist Wilhelm von Humboldt, which aimed to create a universal sense of language on the basis of comparative linguistic studies, was also important. There are, on the whole, two types of constitutional democracies in relation to comparative law. First, constitutional nationalism, which assumes that each nation has evolved under different circumstances, whether social, political, economic, cultural or historical, and therefore laws that solve the problems of one nation, cannot be applied to solve the problems of another nation. Second, constitutional cosmopolitanism,[28] in which it is assumed that the different cultures of the world are all subdivisions of a great civilization and that, therefore, although one legal system is different from another to some extent, the basic principles and rules that govern human behavior and state institutions remain the same. Even Dicey`s introduction to constitutional law ventured into comparative studies. Interestingly, Dicey`s misunderstanding of the French system can be compared to Montesquieu`s inspiring mistakes regarding checks and balances in Britain a century earlier.

With the establishment of positive constitutional law in the nineteenth century, international comparison lost much of its appeal, and the jurisprudence and practices of public law became increasingly self-referential, as if the existence of a national constitution had rendered foreign law irrelevant. The interest in comparison, motivated by the shift to a values-based approach, maintained comparative interest even after World War II as part of Cold War thinking, when liberal democracies defended their system against communist totalitarianism. The post-war period was marked by an international human rights revolution with various waves of state-building and democratization, combined with an increasing legalization of constitutional law. This comparative interest was also inspired by the increased protection of fundamental rights adopted by the U.S. Supreme Court in the early 1940s. The English reader will be interested to know that some of the issues currently being dealt with in the United States are also of immediate importance in the United Kingdom. The first concerns the preservation of our civil liberties in the era of the «Cold War». In order for constitutional legislators and interpreters to make convincing and optimal use of the foreign constitutional documents that they must or want to take into account, it is necessary that they become familiar with them and be able to assess the advantages that a particular foreign speaker may have in a particular decision-making body. This probably requires both understanding how a foreign constitutional norm plays a role in its own institutional environment and how it compares to seemingly similar norms in its own constitutional system and other relevant constitutional systems. Constitutional legislators and judges use institutional models, structures, processes, arguments and doctrines that come from outside their own jurisdiction, and they need sufficient knowledge of these documents to justify such use for themselves and for the public to which they must respond.

In addition, judges can refine their relative knowledge and appreciation of foreign documents through dialogues with constitutional judges from different countries and by referring to relevant comparative studies, analyses and evaluations of the above-mentioned documents in the work of the constitutional experts compared. The latter scientists approach the relevant material as observers, treating it from a descriptive or prescriptive point of view. From a descriptive point of view, the researcher systematically studies the comparative constitutional work that participants perform and performs a range of tasks from classification to critical evaluation. For example, a scientist may distinguish between areas or topics that involve a lot of comparison and those that result in minimal comparison. Or a researcher may criticize existing comparisons in a particular area, such as freedom of speech, if he concludes that constitutional judges base comparisons on superficial similarities while ignoring less obvious but much more important differences. The role of comparative public law is very evident in the Indian Constitution. During the drafting of the Indian Constitution, the discussion on the preamble[6], fundamental rights[7], guiding principles of state policy[8], parliamentary form of government[9], federalism[10], judicial review[11], amendments[12], equality before the law[13], equality of legal protection[14], etc. were adopted mainly after a comparative analysis of constitutional laws in the United States of America. United Kingdom, Canada, Ireland, Australia and others. Comparing governments has become a goal intended to satisfy intelligent curiosity and to stimulate some change.