It is well settled in Anglo-American law that national courts are competent, in general, to adjudicate rights and duties with respect to all things or persons found within the territory which the process of the court controls. Exceptions find an especial justification in considerations of national or international convenience. A situation which seems to have been insufficiently considered, however, is presented by the case of the thing or person which has been seized or arrested abroad, in violation of international law, and brought within the state and thus within reach of the process of the state's courts. Should the courts be considered competent, on the basis of physical presence thus procured, to adjudicate in the usual way?
The student or practitioner whose interest is primarily in the interpretation and application of the law of nations is often prone to dismiss fundamental concepts as a matter of mere theoretical importance. This is a serious mistake. No one is capable of understanding the interpretations and applications of the law of nations which have been made in judicial decisions, national and international, in arbitrations, and in international incidents, unless he has some knowledge of the fundamental concepts of the science and of the conditions under which those concepts have developed. Concepts, in truth, are as much a part of the fabric of international jurisprudence as the intricate and confused records of international conduct. If they are no longer its warp and woof, they provide at least the necessary patterns.