Since the mental powers of man are unlimited they are more important, once they get started, than the powers of nature, which are limited and stationary. Man has endless capacity, through his dynamic mental tendencies to develop the physical resources of the earth.
The birth rate depends on food supply. In hot countries, where less food per capita is required than in cold countries, and where an abundance of food exists, the birth rate is very high. In cold countries highly carbonized food is necessary, but this food is largely animal in origin and great risk is involved in procuring it. Hence the people of cold countries become adventuresome.[XV-8]
By the study of physical laws it is possible to determine what the national food of a country will be. In India, for example, the physical conditions are decidedly favorable to the growth of rice, which is the most nutritive of all cereals, and which, consequently, is a causal factor in a high birth rate.
But where there is a cheap national food, the increase in population becomes very great. As a result, there are multitudes of people who are able to keep just above the subsistence level. A few individuals who understand the operation of these physical laws are able to manipulate the multitudes in such a way as to make themselves immensely wealthy. Since wealth, after intellect, is the most permanent source of power, a great inequality of wealth has been accompanied by a corresponding inequality of social and political power.[XV-9] It produces classes and even castes. Poverty provokes contempt. Class conflict results. The poor are ground low, murmur, and are again subjected to ignominy. Under such conditions democracy has a hard struggle. When physical conditions favor one class, that class will constitute itself the government and bitterly oppose the extension of government to all other classes. In Europe there was no cheap national food, no blind multiplication of population, and hence no such disparity between classes as in India. In Europe it has been easier for democratic movements to spread.
Early civilization developed in the Euphrates valley, the Nile valley, and in the exceedingly fertile regions of Peru, Central America, and Mexico. Modern civilization is found largely in fertile river valleys, such as the Thames, Seine, Rhine, Po, Danube, Hudson, Mississippi. But in the Amazon valley, the fertility of soil has not invited the growth of a large population. The trade winds have brought in a superabundance of moisture, producing torrential rains, and a luxuriance of plant life and a complexity of virile animal life which thus far have defied the skill of man to overcome.
The fourth physical factor which Buckle presents is the general aspects of nature. Of these the first class excites the imagination and the second stimulates the rational operations of the intellect.[XV-10] In regard to natural phenomena it may be said that whatever inspires feelings of terror, of the vague and uncontrollable, and of great wonder tends to inflame the imagination and to cause it to dominate the intellectual processes. Where nature is continually exhibiting its power, man feels his inferiority. He assumes a helpless attitude. He ceases to inquire or to think. His imagination, rather than his reason, reigns. On the other hand, where nature works smoothly and quietly, man begins to assert his individuality. He even essays to dominate nature and other men. His cognition develops and his volition expresses itself vigorously.
All early civilizations were located in the tropics or sub-tropics. In these regions nature is dangerous to man. Earthquakes, tempests, hurricanes, pestilences prevail. Consequently, the imagination of man takes exaggerated forms. The judgment is overbalanced; thought is paralyzed. The mind is continually thrown into a frantic state. These reactions throw human life into feeling molds, into poetic rather than scientific forms. Religious feelings are promoted. The leading religions of the world originated in the sub-tropical and tropical regions of the earth.
East Indian literature and thought illustrate the effect of nature upon the feelings and the imagination. The works of the East Indians on grammar, law, history, medicine, even on mathematics, geography, and metaphysics are nearly all poems.[XV-11] Prose writing is despised. The Sanscrit language boasts of more numerous and more complicated metres than can any European tongue. The East Indian literature is even calculated to set the reason of man at defiance.[XV-12]
The imagination, for example, in India has produced an exaggerated respect for the past; it is this situation which has led poets to describe a Golden Age in the remote past. In the literature of India there is recorded the statement that in ancient times the average length of life of common men was 80,000 years. There are instances of poets who lived to be half a million years old.
In Greece, on the other hand, nature is more quiet and the mind of man functioned in a reasoning way. In the North Temperate zone science developed. “The climate was more healthy; earthquakes were less frequent; hurricanes were less disastrous; wild beasts and noxious animals less abundant.”[XV-13] Buckle, in other words, insists that everywhere the hand of nature is upon the mind of man.