[Sidenote:  Local and remote geographic factors.]

Every country forms an independent whole, and as such finds its national history influenced by its local climate, soil, relief, its location whether inland or maritime, its river highways, and its boundaries of mountain, sea, or desert.  But it is also a link in a great chain of lands, and therefore may feel a shock or vibration imparted at the remotest end.  The gradual desiccation of western Asia which took a fresh start about 2,000 years ago caused that great exodus and displacement of peoples known as the Voelkerwanderung, and thus contributed to the downfall of Rome; it was one factor in the Saxon conquest of Britain and the final peopling of central Europe.  The impact of the Turkish hordes hurling themselves against the defenses of Constantinople in 1453 was felt only forty years afterward by the far-off shores of savage America.  Earlier still it reached England as the revival of learning, and it gave Portugal a shock which started its navigators towards the Cape of Good Hope in their search for a sea route to India.  The history of South Africa is intimately connected with the Isthmus of Suez.  It owes its Portuguese, Dutch, and English populations to that barrier on the Mediterranean pathway to the Orient; its importance as a way station on the outside route to India fluctuates with every crisis in the history of Suez.

[Sidenote:  Direct and indirect effects of environment.]

The geographic factors in history appear now as conspicuous direct effects of environment, such as the forest warfare of the American Indian or the irrigation works of the Pueblo tribes, now as a group of indirect effects, operating through the economic, social and political activities of a people.  These remoter secondary results are often of supreme importance; they are the ones which give the final stamp to the national temperament and character, and yet in them the causal connection between environment and development is far from obvious.  They have, therefore, presented pitfalls to the precipitate theorizer.  He has either interpreted them as the direct effect of some geographic cause from which they were wholly divorced and thus arrived at conclusions which further investigation failed to sustain; or seeing no direct and obvious connection, he has denied the possibility of a generalization.

Montesquieu ascribes the immutability of religion, manners, custom and laws in India and other Oriental countries to their warm climate.[17] Buckle attributes a highly wrought imagination and gross superstition to all people, like those of India, living in the presence of great mountains and vast plains, knowing Nature only in its overpowering aspects, which excite the fancy and paralyze reason.  He finds, on the other hand, an early predominance of reason in the inhabitants of a country like ancient Greece, where natural features are on a small scale, more comprehensible,