I haven’t the slightest intention of answering these questions here; I freely admit that many of them leave me perplexed, but I dogmatically maintain that it is by pondering such questions, by studying the comparisons they suggest, that the frontier problem is to be understood by the historian and comprehended by the statesman. Without such comparisons the student of the problem in any one field is less apt to judge a particular episode rightly than a man with no knowledge and good intentions. The path to wisdom and sure-footed action must be founded on the rock of exact knowledge, but it must be platted on a wide-spread survey. All life reveals the irony of wisdom attained only by the experience to deal with which it was needed. It is but today we have this rich storehouse of experimental frontier building, and tomorrow we will have no frontier. It might seem that we could let a dead past bury its dead, that the study of frontier episodes, however successful, has become sheer antiquarianism. Such a view, however, minimizes the world frontier that remains and the time and effort that will be required in its conquest. As in science, so with the material world, the nineteenth century made easy sweeping advances; it left much that was difficult for the slower and more laborious labors of the twentieth. It overlooks the facts that great masses of the world’s inhabitants today count the experience of meeting the wild first-hand among the most important of their nearby inheritances, that the frontier set its mark upon them or their parents, or grandparents, and that the present generation cannot be understood unless the frontier is understood. Still more important is the consideration that in many instances the frontier merely localizes problems that are general. The factors with which this paper has dealt are peculiar to the frontier only in that the creditors are assembled in one section, the debtors in another. This is an important peculiarity in large part because it isolates the characteristics of each, and makes them easier of study. When the world has been fully occupied, new frontiers will appear, are already appearing. Natural resources now undreamed of will need capital and labor for their exploitation, will be susceptible of development in more than one way, and will raise problems of control. Our experiences with the rude and simple problem of the first occupation of a waste area will seem as geometry to calculus compared with those raised by these new frontiers, but will be as essential to a wise handling of them as geometry is to calculus.