Legal history teaches two doctrines, which seem at first glance diametrically opposed to each other, with reference to the current agitation concerning the dangers of federal encroachment. First, that the agitation, in so far as it is called out by a temporary accidental state of affairs due to the war, is ephemeral. On the other hand, the essential facts involved are of a type that are always with us. In other words, federal encroachment, when stripped of the mask and guise that temporarily makes it seem dreadful, is a perfectly natural phenomenon quite familiar to students of Anglo-American law, and, for that matter, of other legal systems.