To a certain degree they each formed a check on the excessive tendencies of the other. But, the power of each fairly established, they often united to set very hurtful limits to spontaneous action. The king used his power to the common injury, and the priests their knowledge to the common debasement. The first exhausted the sources of prosperity and growth among his people to gratify his caprices and pleasures, and the priesthood promoted degrading superstitions and a gross idolatry to strengthen their influence. It was for the interest of both to keep the people in pupilage, and check all tendencies to independent action or thought. Had it been possible for them to be wise and high-minded, the race would have been saved many centuries of debasement and misery. 11. These evils were, in some degree, checked by influences which have ever since been the mainspring of progress—_War_ and _Commerce_. In early times, relationships of blood or of immediate interest were the chief bonds among men. All outside the family, tribe, or nation were usually held as enemies; and passion, interest, or ambition in the ruler led to constant conflict. But the shock of peoples awakened their minds, made them acquainted with each other, made their inventions and arts in some degree common property, and mingled the thought and blood of different races; and this greatly enlarged the ideas and capacities of both conquerors and conquered. The acquaintance made in this way, with men and countries, led to an interchange of products, during quiet times, and trade and commerce soon sprung up. This, appealing to the best interests and instincts of the most enterprising among the people, has always been a powerful instrument of advancement. It led to distant voyages and travels, to observation and intercourse, with a view to pecuniary advantage, to inventions and improvements in industry and art, that kept the peoples so related in a state of constant progress. 12. A growing population required increasing attention to agriculture and the mechanic arts, and increasing wealth led to architectural display and the increase of instruments of luxury, the production of which disciplined the skill of the artisan and contributed to the general growth. All these were the elements and foundation of civilization. An organization commenced, and a state founded, the king soon found leisure to look about and envy the wealth and territories of his neighbor. He made war and commenced a career of conquest, or fell, under defeat, into his neighbor’s hand, when time took a step forward, and a new consolidation, wider and higher than the former, was laid on a broader base. Slowly but surely an advance was made.