America, and the steppes of Russia, the scarcity of subsistence necessitates a nomadic life. In this patriarchial form of existence the size of the community is limited by the productiveness of the soil, as illustrated in Genesis 13: 5-11. Fixed relationships are therefore unknown, and hence the political and social order called the state is impossible.
Each of the great river valleys of antiquity developed an independent civilization, Egypt first by reason of its tropical location, closely followed by China and the Tigro-Euphrates basin, lying five degrees farther north. The beginnings of Chinese culture were equally promising with those of the other great nations of antiquity. The art of writing was probably originated by the Chinese, while the elements of mathematics and astronomy, the art of printing and various manufactures, were known to them centuries before they reached Europe. The geographical isolation of China, however, put an effectual barrier to progress, resulting in a sort of inversion of character, whereby reverence for precedent took the place of progressive development. As an instance of this inversion, it is related of one of the Chinese emperors that when he wished to confer honors upon his prime minister he conferred them upon the minister's father. Chinese culture has petrified almost at the outset, and is therefore of no significance except as a case of arrested development, due largely if not wholly to geographic limitations.
In contrast to China, the civilizations originating in the valleys of the Nile and Euphrates found a natural outlet eastward and northward by way of the Mediterranean. Here culture in all its phases reflected the influence of the soil. Religion took the form of a gross nature worship, the divinities being the great rivers, the sun and moon, and other natural sources from which their physical wants were supplied, while arts and manufactures were also limited to the practical and prosaic. In Egypt the peculiar physical conditions presented by the annual overflow of the Nile led to the invention of surveying, and of necessity to the elements of arithmetic and geometry required to apply it. In architecture also the effort to orient their temples gave rise to certain fundamental geometric theorems, still in use, such as the properties of right-angled triangles, while in art the enlargement of small drawings or paintings for their temple walls was accomplished by means of a network of squares closely related to the modern Cartesian system of coordinates. The entire absence of rainfall and consequent clearness of atmosphere also had an important effect in directing the attention of the Egyptians to the heavens, which, supplemented by the oriental use of the roof as a terrace, led to the study of astronomy.
In Chaldea the similarity of race and physical conditions to those in Egypt led to identical results, the earliest fragments of Chaldean literature disclosing a considerable knowledge of mathematics, astron-
