the arabian peninsula was crisscrossed with caravan routes. of these, two were important. the first ran alongside the persian gulf, then alongside the tigris [perhaps the author meant the euphrates, for it is hard to see why a west-bound caravan should travel alongside the tigris. -tr.] and then crossed the syrian desert towards palestine. it was properly called "the eastern route." the other route ran along the shore of the red sea and was properly called "the western route." on these two main routes, world trade ran between east and west carrying products and goods in both directions. these two routes provided the desert with income and prosperity. the peoples of the west, however, lived in total ignorance of the routes which their own trade took. none of them, or of their eastern neighbors, ever penetrated the desert territory unless it be the case of an adventurer who had no concern for his own life. a number of adventurers perished in trying the desert labyrinth in vain. the hardships which such travel entailed were unbearable except to those who had been accustomed to desert life from a tender age. a man accustomed to the luxuries of town living cannot be expected to bear the discomfort of these barren mountains separated from the red sea only by the narrow passages of tihamah [the narrow plain alongside the east coast of the red sea, separating the latter from the hijaz mountain chain and the desert beyond. -tr.], and leading through naked rocks to the apparently infinite expanse of most arid and desolate desert. a man accustomed to a political order guaranteeing the security of all inhabitants at all times cannot be expected to bear the terror and lawlessness of the desert, devoid as it is of political order, and whose inhabitants live as utterly independent tribes, clans nay individuals except where their relations to one another come under the jurisdiction of tribal law, or some ad hoc convention of a strong protector. the desert had never known any urban order such as we enjoy in our modern cities. its people lived in the shadow of retributive justice. they repelled attack by attack, and they sought to prevent aggression by the fear of counter-aggressions. the weak had no chance unless somebody took them under protection. such a life does not encourage anyone to try it, nor does it invite anyone to learn of it in any detail. that is why the arabian peninsula remained an unknown continent throughout the world until the circumstances of history permitted its people, after the advent of muhammad, may god's peace and blessing be upon him, to migrate and thus tell about their country and give the world the information it lacked.