Two schools may be said to be opposing one another in the science of International Law with regard to the relations between International and Municipal Law. There are, firstly, a number of publicists who assert that International Law is above Municipal Law and that, therefore, the rules of the former are stronger than the rules of the latter. Accordingly, a Municipal Court would have to apply the rules of International Law whether they are expressly or implicitly recognised by the Municipal Law of the State concerned or not, and even in a case where there is a decided conflict between a rule of Municipal Law and a rule of International Law. "_International Law overrules Municipal Law_" must be said to be the maxim of this school of thought. There are, secondly, other publicists who maintain that _International Law and Municipal Law are two essentially different bodies of law_ which have nothing in common but that they are both branches--but separate branches!--of the tree of Law. The rules of International Law are never, therefore, _per se_ part and parcel of the Municipal Law of a State, and a Municipal Court cannot apply the rules of International Law unless they have been adopted, either expressly or implicitly, by the Municipal Law of the State concerned. Should there be a conflict between a rule of International Law and a rule of Municipal Law, a Municipal Court can only apply the rule of Municipal Law, leaving it to the legislature of its State to do away with the conflict by altering the Municipal Law. I believe that the teaching of the latter school of thought is correct[2] since International and Municipal Law differ as regards their sources, the relations they regulate, and the substance of their law. Rules of International Law can, therefore, only be applied by Municipal Courts in their administration of the law in case and in so far as such rules have been adopted into Municipal Law either by a special Act of the legislature, or by custom, or implicitly. [2] See my treatise on International Law, 2nd edition (1912), Vol. I, Sec.Sec.20-25.