Many instances can doubtless be found in which both these propositions are true. The intervention of a narrow forth has certainly been one of the main causes of the inveterate estrangement of the English and the Irish: it has been largely responsible for the conventional hostility between England and France. But quite as many instances can be found in which the peoples on two sides of a strait or narrow sea have been on friendly terms. The generalization about mountains is equally unscientific. Nor is the inverse in either case any truer, viz. that States which are not separated from each other, either by narrow seas or by mountains, are therefore naturally friends. The fact is that in all such cases a great many causes are at work, of which geographical position or environment is but one. A safer procedure is that of deduction only from established facts. Macaulay, in his Frederick the Great, wrote in his pictorial manner, but with incontrovertible truth:—
Some states have been enabled by their geographical position to defend themselves with advantage against immense forces. The sea has repeatedly protected England against the fury of the whole Continent. The Venetian Government, driven from its possessions on the land, could still bid defiance to the Confederacy of Cambray from the arsenal amid the lagoons. More than one great and well appointed army, which regarded the shepherds of Switzerland as an easy prey, has perished in the passes of the Alps.
Here the philosophy of Frontiers is demonstrated by concrete facts.
Origin of Frontiers.
If we start with the dawn of history, at least in Europe, it is not difficult to trace the conditions under which the first Frontiers came into being. The existing peoples of