 Ladies and gentlemen, first of all, let me warmly welcome each and every one of you and thank you very much for having enrolled for this course. The course is about international law, but let me begin with two numbers which have very little to do with any law. The first number is this one, 7,226,259,052. The second number is 3,153,600,000. What are those numbers? You've probably guessed that the first number is the approximate number of human beings living on Earth on the day this video was recorded in 2015. But what about the second number? It could be the world population a few decades ago, but this is not what I intended to convey. The 3 billion plus figure is the number of seconds in 100 years, not counting the leap years. 60 seconds in one minute, multiplied by 60 for one hour, multiplied by 24 for one day, multiplied by 365 for one year, multiplied by 100. Now look at those two figures together and try to grasp what humanity very concretely means today at the beginning of the 21st century. Currently, there are more than twice as many human beings on the planet than there are seconds in the life of 100 years. In other words, would you live 100 years and would you spend your entire long life of 100 years from birth to death, only paying one second attention to every other fellow human being without eating, sleeping, playing, learning, working and all the rest? That would still not be enough. You would still only have met for one second each with less than half of humanity. Well just think about it for a second. This is what humanity concretely means in this time and age. It is huge. So to a large extent, humanity understood as the collection of living human beings. Humanity remains an abstraction. We live, we die and what do we really know and experience about humanity? Only a tiny fraction of it. However, we can all relate to each other. We all participate in humanity and since 1948 the Universal Declaration of Human Rights proclaims that all human beings are born free and equal in dignity and rights. And we know that it is far from being a given in all parts of the world for each and every one of our fellow humans. In this course, we're not going to speak much about humanity and about human rights. Rather the course will be mostly about abstract legal entities like states or international organizations and their relations under the law. This may sound very abstract and remote from our shared humanity, but let me make this very clear from the start. International law may be mainly about relations between states, but beyond the mediation of states international law is ultimately about us human beings. It is about us living separately in states, but it is about us living together on this planet. And as the planet shrinks and the world population expands, never before has it been so important in my view to educate in international law and to raise the public awareness about it. This is one of the purposes of this course. I sincerely hope that you'll enjoy it and find it valuable.