 Welcome back. Let me sum up the two elements theory in the formation of customer international law. The first element is said to be the objective element. It is about what is usually done. In international law what is usually done is referred to as the practice of states. Practice can be made of actions or even abstentions in actions. This is because the fact of abstaining from doing something is already doing something. Practice can be found in domestic legislation, in decrees, in the behavior of governmental agencies, of the armed forces, in judgments of domestic courts, etc. As long as the factual or legal behavior can be said to be the behavior of states rather than the behavior of individuals or corporations, we have practice that can count as far as the creation of custom is concerned. But the behavior of states about individuals and about corporations or about other non-state actors, that behavior of states may also count as practice. However, one instance of practice is not ineth. Practice needs to be recurrent, both in time and over space. Practice must be general. Remember the words of article 38 paragraph 1b, international custom as evidence of a general practice accepted as law. Well this means that the behavior taken into account must be regular and consistent over time. It must be repeated. There must be a pattern of similar acts, repetition, consistency, is at the heart of the notion of custom. Therefore the idea that custom can be instantaneous is very much alien to it. Furthermore, the settled practice must not only exist in time but also over space. That is, it must not only be repeated by one or two states but it must be shared by a real plurality of states. Not necessarily a plurality comprising all states but at least a plurality comprising states that are most likely to be specially affected by the rule emerging from the practice. To take a straightforward example, for the delimitation of maritime zones, the practice of landlocked states, states without a coast, that practice can be disregarded, although more so that it is unlikely to exist. But this is precisely the point. It does not matter that landlocked states, despite being numerous, have no practice about maritime delimitation for a customary rule about that subject to emerge. The practice must not only be general, it must also be accepted as law, as Article 38 puts it. This is the second element in the two-element theory of international custom and it is said to be the subjective element of custom. In Latin it is referred to as the Opinio Juris Sive Necessitatis. Using Latin words sounds serious but it makes things even more mysterious. So what does this actually mean? The point is really the difference between, on the one hand, a pattern of practice which makes a usage, a habit, a tradition, things are done because they are usually done that way. And on the other hand, a pattern of practice which makes a legal obligation enshrined in custom. Things are done because they ought to be done that way. What makes the difference between the two is this subjective element. As you have seen from the North Sea Continental Shelf case, the ICJ says that the states concerned must feel that they are conforming to what amounts to a legal obligation. Now this is quite peculiar for two reasons. First, it is strange to say that states, after all, are only abstract legal entities have feelings as if they were human beings. But the idea is that states must have somehow express themselves about the legal dimension and meaning of their practice. Second, there is a logical trap in saying that the second constitutive element of custom is the sense of a legal duty to conform with the practice. Indeed, how could one have the sense that the practice is obligatory when the issue is precisely the emergence of an obligation? Is it not putting the cart before the horse to say that states must be of the opinion that what they do is compulsory when what is actually at stake is the creation through the combination of practice and opinionaries of a binding obligation in the form of a rule of custom international law? To get out of this logical trap at the stage of the emergence of custom, let me submit that it is better to consider that the opinionaries is not so much the feeling of complying with what the law requires, which would be impossible since the law is in the process of emerging, but rather the opinionaries should be understood as the intent to make custom.