=Extent of the Biblical World.= In its widest bounds, the biblical world included practically all the important centres of early human civilization. Its western outpost was the Phœnician city of Tarshish in southern Spain (about 5° west longitude) and its eastern outpost did not extend beyond the Caspian Sea and Persian Gulf (about 55° east longitude). Its southern horizon was bounded by the land of Ethiopia (about 5° south latitude) and its northern by the Black Sea (about 45° north altitude). Thus the Old and New Testament world extended fully sixty degrees from east to west, but at the most not more than fifty degrees from north to south. With the exception of Arabia, all of these lands gather about the Mediterranean, for although the waters of the Tigris and the Euphrates ultimately find their way into the Indian Ocean, the people living in these fertile valleys ever looked toward the Mediterranean and for the most part found their field for conquest and commerce in the west rather than in the east and south. =Conditions Favorable to Early Civilizations.= The greater part of this ancient world consisted of wastes of water, of burning sands or of dry, rocky, pasture lands. Less than one-fifth was arable soil, and yet the tillable strips along the river valleys on the eastern and northern Mediterranean were extremely fertile. Here in four of five favored centres were supplied in varying measure the conditions requisite for a strong primitive civilization: (1) a warm, but not enervating climate; (2) a fertile and easily cultivated territory which enabled the inhabitants to store up a surplus of the things necessary for life; (3) a geographical unity that made possible a homogeneous and closely knit political and social organization; (4) a pressure from without which spurred the people on to constant activity and effort; (5) an opportunity for expansion and for intercommunication with other strong nations. The result was that the lands about the eastern Mediterranean were the scenes of the world's earliest culture and history. From these centres emanated the great civic, political, intellectual, artistic, moral, and religious ideas and ideals that still strongly influence the life and faith of the nations that rule the world. The character of each of these early civilizations was in turn largely shaped by the natural environment amidst which it arose.