Egypt kept her inhabitants secluded within hard and fast limits; beyond the hills began the desert. With the increasing number of inhabitants the attempt must have been made to set low-lying marshy districts free from the excess of water, and to make fruitful the higher parts of the valley beyond the reach of the inundations by bringing the water upon them. Experience quickly taught that the plot produced the most abundant fruits on which the inundation had continued longest, and consequently had time to deposit the thickest layer of mud. Hence the attempt was made to keep the water longer on the soil by means of dykes. These objects, in regard to which the interests of the several districts differed, and which required the combination of large masses of operatives to carry them out, must have made the need of a supreme decisive and executive power felt earlier in Egypt than in other lands. The inhabitants of Egypt found themselves surrounded by a solemn landscape, before fixed and unchanging forms and outlines, in the midst of natural phenomena, recurring with invariable regularity and always in the same succession. Such surroundings and impressions must have stamped on the young life of a ripening nation a settled, stern, and unvarying character. When the original unity and society of life, which comprises all members of the family and in the tribe, has been broken through--when at the beginning of their settled life some have turned their attention to agriculture and cattle, others to hunting and war, others again to the fulfilment of religious duties--the sons are wont to carry on the vocation of the fathers. This is the rule often in far more advanced periods; and simpler conditions of life compel the son to carry on the life of the father, in whose occupation he has grown up. In such times there is no mode of teaching and instruction but through the family. In this way the tribes and the nation part into separate circles, which carry on as an inheritance the mode of life derived from their forefathers. These divisions of occupation, of vocation, and mode of life could be carried out earlier and with greater sharpness in Egypt than in other lands.