Competition law is one of the most important parts of economic law and regulation. A historical review of the developments of the economics and public law indicates that public law principles of competition law are influenced by theories of state and theories of justice. In this respect, various legal and political systems on the basis of some philosophical and political principles have tried to justify and apply competition law. The classical liberals relying on the principle of not inflecting harm on others justifies competition law while the proponents of distributive justice on the basis of concepts of equality and just distribution of wealth defend competition law. The advocates of the theories of justice are in favor of competition law to extent that it lead to justice in the market place. This paper investigates how competition law is justified under the above theories.

Public Law has some unique characteristics which draws a distinction between it and other branches of law. It proposes this question، that whether these characteristics provide a specific way of interpretation for public law. One can answer to this question that although public law does not have specific method of interpretation، it enjoys different interpretational schools in different ways. For example، nowadays، the inefficiency of Originalism in some area of public law is well demonstrated. In constitutional law، the key role of constitution as a most important document in distribution of power، freedoms and rights and its ambiguous and general terms presents some problems for Orginalism، which believes in determination of meaning. In administrative law، regarding the fundamental developments in the modern administration and the hesitation about some premises of it-such as rule of law and separation of power-Originalism faces with a crisis. Therefore، there are some growing trends toward dynamic ways of interpretation. This debate plays a pivotal role in distribution of power between judiciary and administrative institutions.

Interdisciplinary studies are one of the new fields in epistemology, which have gone beyond the realm of classical studies and offer us a new methodology. Public policy is an interdisciplinary concept in human sciences that is known for its contextual application, as a "specialized concept" to an "academic discipline". This situation shows its importance and high capacity among the concepts of human sciences. Understanding such importance, the present paper seeks to explore this concept in the knowledge of public law. In this regard, this paper achieved these results using a descriptive-analytical method. First; the interdisciplinary nature of public policy makes it difficult to properly and accurately understand this concept in public law. Secondly; since the first place of this concept is in other sciences, so public law can use its capacity only as a succedent knowledge. Thirdly; the reading of the mentioned concept in public law can be evaluated as legal based on its practical context in law, such as judicial policies. Therefore, the concept in public law alone cannot be considered as a specialized establishment. Fourth; it seems that the concepts of politics and policy-making at the moment when they are placed as an interdisciplinary concept among specific sciences have a conceptual color and smell and can be discussed according to the context of a specific knowledge.

To understand the invention as a legal concept, first its legal nature must be known, and then the rights of the inventor can be recognized. The study of patent law and the rights of inventors began in the second part of the 19th century and was developed gradually during the years with ratification of numerous international instruments. Following the ratification of various conventions in this field within the framework of international law, different conventions have been adopted and codified, protecting literary and artistic property as well as the rights of the author. Among these conventions, the multilateral Strasbourg Patent Convention (1963) is of significant importance, and has been the foundation of an evolution of vertical and horizontal perspectives at the European level. From the vertical point of view, the governing European Law is considered as the applicable law between member countries. However, from the horizontal perspective, the comparative examination of the legislations of some important countries must be considered as examples of state legislations. That is why the French, Belgian and German legislations have been comparatively studied in this article. Another issue considered in this study, is the legal nature of the inventor’s rights which began with the Resolution N° 1 of "Congres de Paris-1877". Our efforts to identify all legal aspects of the concept of invention, as well as the rights of the inventor, will result in a better understanding of the related diverse aspects of intellectual, literary, and industrial property.

Public law as a discipline of legal science which considers public matters – in confront with private matter, is established in ancient Rome and influenced deeply the European history. In the first step, its basic concepts, such as Imperium and Jurisdictio, and its outlook toward the relation of power and law, gave way to the concept of sovereignty as a monopoly of approving, changing and abolishing of statutes. It leads to the establishment of authoritative governments. In the second step, it provides the proponents of absolutism with legal arguments against their traditional and new rivals. At the end, it were the constitutionalists who promote Roman law with some principle of roman private and corporate law and reinterpretation of old concepts in shadow of new needs of era to apply them against their oponents. Finally, these disputes resulted in our understanding of modern state and representation and Roman law, despite to its flexibility, leaved its lasting impression, i. e. formulation of political conflicts in the legal language.

Law as the regulator science of society will be necessary to change the approach and approach with the transformation of social communication. The occurrence of developments, especially in the field of public law, at a rate that does not allow legislation to adapt and enact whit them; make the other sources of law, such as precedent, have different functions. The leading article sought to investigate and analyze whether the precedent in contemporary public law had notable changes? and if the answer is positive, in what forms? Finding shows yes answer to this question following the developments in the contemporary world and their impact on the science of law that recognized the jurisdiction of the precedent in three parts: make a new norms, complete the existing norms and protecting the rights and freedoms of individuals and consequently the change in the status of judicial practice among the sources of public law and its promotion it happened.

One of the main challenges in attracting investment is maintaining the interests of foreign investment while protecting the public interest of the host country. The combination of these two is difficult and controversial. There is no comprehensive, agreed-upon definition of public interest in foreign investment law, although most investment agreements include the term "public purpose. " In this article, we will examine the nature of the criterion of "public purpose " as one of the main principles of nationalization and will discuss the difference between the concept of public purpose and national security. The existence of a public purpose is one of the basic conditions for the legitimacy of the nationalization of capital and natural resources, while in international law there is no objective and clear criterion for evaluating the public purpose. Therefore, the decision on the legitimacy of expropriation based on the public purpose is practically left to the governments themselves to decide by exercising their authority. And the nationalizing state's recognition of the public purpose when nationalizing foreign property is based on the government's sovereignty over natural resources, but this does not prevent a foreign investor from objecting to it. The doctrines and procedures of international arbitration should also be referred to the domestic law of the nationalizing country.