*This article was submitted in the Prize Essay Contest, 1935.
"Every truth has practical consequences and these are the test of its truth."—Pierce’s Principle
In their relations with each other, civilized states feel bound by certain principles and rules of conduct declaratory thereof to which the term international law is applied. International law is a weaker law than national law because it lacks a central authority with power to make laws, interpret, and enforce them. To be part of international law a principle or rule of conduct must have been accepted by the several states of the family of nations as the law governing their mutual relations. For its enforcement international law depends on the pressure of world opinion and on the fear that a state whose rights have been violated may resort to retaliation or war. Important consequences follow.