The task of codifying international law is so vast, the subject thus named so uncertain in nature and in limits, language so imperfect and misleading, and human reason so puny, that a person who addresses himself to the business with the intention of elaborating concrete expressions of the law findshimself with no solid foothold to start from, no certain direction to take, and no clear conviction as to how best to work. In the present attempt to study the problem of codification of international law in a few of its aspects, the writer has taken one topic only, the treaty, thinking that here we have phenomena in plenty and that discussion thereof may be a fruitful preliminary procedure. For even here, at the very outset, we are confronted with primary questions which throw us back to the very threshold as it were of the whole subject.