During his boyhood, Mohammed had plenty of opportunities for observing the condition of affairs, and, thanks to his privilege of travelling with the caravans, was even able to notice the contrast between the conditions of his own people and those of the more peaceable, prosperous nations. He frequently attended upon his uncle in the fighting that often occurred between the tribes, and so gained the knowledge of military strategy which proved to be so useful at a later time. Margoliouth suggests that the two most important lessons the "prophet" learned at this time were the necessity of settling affairs of blood by some expedient less wasteful, and more satisfactory than that which was illustrated by the war of Fizar, and that war should be regarded not as a game, but as a mode of obtaining decisive results. The varied experiences he passed through on his caravan journeys did much to influence his future policy; indeed, it appears that all influences brought to bear upon his early life were forces that moulded and equipped him for the office he was to fill. He was keenly observant, and wonderfully accurate in his inferences, especially in his estimate of the characters of men with whom he had to deal. He seemed to lack initiative, for he was always reluctant to take action in any important undertaking; but once the initial step was taken, he pressed forward with indomitable courage. In his business transactions he proved himself to be shrewd and tactful, and by his fidelity, patience, and self-confidence, gained the respect and esteem of his immediate fellows. Khadijah, a rich widow, having entrusted Mohammed with the control of an important caravan, and finding how admirably he had performed his part, wisely concluded that her interests would be furthered if he had a share in them. Hence their marriage, which happy arrangement proved to be mutually blessed and successful. It vastly improved Mohammed's social standing, raising him to a position of equality with the leading men of the city. For many years he was content to live quietly as an ordinary citizen, engrossed in the accumulation of wealth by legitimate trading. II.--THE "CALL" TO THE PROPHETIC OFFICE.