 After the first and second weeks you are no more familiar with the history of international law, its fundamental structure and also its subjects. This week is about making international law. Of course the topics of the first three weeks of this course are very much interrelated. Indeed law is always man-made and it is needed to understand who are the players of and the subjects in order to understand who can make law and how law is made. This week is dedicated to the issue of lawmaking in the international community. That is what are the processes through which rules of international law come to existence. It is not about lawmaking in general but about making law that can be considered as having an international law character. Moreover what will be of interest to us this week is not why such a rule of international law exists and has such or such content why there is such obligation rather than another obligation. It is of course always important to understand the political, the economic, historical or moral contexts leading to the emergence of any specific rule but what can be called the material sources or reasons for the law is not what we are going to look at. Rather we're going to study what most textbooks call the sources of international law in the formal rather than material way. Where does international law come from? How does it come to existence? How is it made? Identifying those formal processes through which rules of international law are created has of course an immediate bearing on the issue of the subjects of international law. This is because the processes that are accepted as processes through which new rules of international law can be created are processes that very much reveal who has the capacity and the authority to make law. In that sense talking about the formal sources of international law is not much different from talking about who is considered to have a full legal personality that is a personality with the active capacity to make law. In that sense also the issue of the sources of international law is deeply political. Of course it does not look like that and as you will see it is in many ways very technical and somehow purely legal and it is important to learn about those legal technicalities and to master them as such because this is what the added value of a professional lawyer is about. However this should not hide the bigger picture of what is at stake in the identification and description of the processes through which international law is made and furthermore it is also important to remember that by studying the various ways by which international law comes into existence we are actually studying what is international law. Indeed Hans Kelsen the great Austrian born jurist and legal philosopher who immigrated first to Switzerland and then to the United States in the 1930s. Hans Kelsen wrote that international law can be defined solely by the ways in which its norms are created. So by learning about the various ways in which international law norms are created we not only learn about those processes as legal technical issues but also we gain a better and deeper understanding of what is international law and what can be expected from it. In the first lesson of this week we'll identify the reasons why lawmaking is a different problem in international law as compared to domestic law and after that we are going to survey the various sources of international law, the various techniques that are used to create new rules of international law. Hence in the second lesson we'll study what is gastro-international law. The third lesson will be about international treaties. What are treaties or are they negotiated, concluded, what are the conditions for their validity etc. After that we'll see what are the general principles of law as a source of international law. The fifth and the sixth lessons will deal with unilateral acts, either unilateral acts of states or unilateral acts of international organizations. As far as the latter are concerned resolutions of the United Nations Security Council will be more specifically mentioned. And finally I'll address the issue of what is often called soft law in international law, that is other acts and other instruments that look like law but are not hard law because they are not the result of the above mentioned usual processes. In other words the theory of the sources of international law has not only an inclusive aspect it also has an exclusive element by saying how law can come into existence, how it is created. It also says what is not law, what does not count as law. And this brings me back to a basic element about the function of any law be it domestic or international law. The theory of sources is deeply political not only because it tells you who has the authority to make law and how law is made but because the function of the law is always and at the same time to limit power and to enable the exercise of power. Law gives reasons for action it helps to justify what is done and at the same time law limits what can be done and delegitimizes what would be done in contradiction of the law. Law justifies and limits power therefore by identifying what count as law and what does not Any theory of sources has an immediate political dimension and impact