722 THE AMERICAN JOURNAL OF SOCIOLOGY
population is a primary requisite to advancing civilization. The temptations and dangers which city growth involves are dangers incident to progress. That nations have succumbed to such temptations is merely an illustration of the fact that every change in the conditions of life brings with it a new strain upon national character requiring increased self-control and discrimination.
Throughout the history of civilization we can readily trace the close relation between the aggregation of population and the development of the arts and sciences. The close association of city life first makes possible the division of labor, and with such division of labor comes increased productive power. Every advance in productive power creates new wants and involves new possibilities of enjoyment. In all the earlier civilizations menial duties were performed by slaves, which set free the energy necessary to supply the wealthy and leisure classes with comforts and luxuries. The possibility of leisure, which becomes a reality through the division of labor, opens new ave- nues of intellectual development. We speak of the country as the best place for meditation and reflection, but constantly lose sight of the fact that it is "the crowd, the hum, the shock of men" that sharpens the intellect, develops inventive genius, stirs commercial activity, and arouses the spirit of cooperation.
The primary incentive to intellectual advance comes from the city. For the mass of the population a constant stimulus is necessary to assure even a small amount of intellectual activity, for left to himself the individual rapidly sinks to the intellectual stagnation characteristic of isolated rural districts. The constant contact of mind with mind, which can only be obtained in the city, is necessary to any general intellectual advance. The social life of our modern cities clearly shows that in the great majorit)- of cases the incentive to intellectual effort comes from without ; the desire to imitate some person or group of persons who have acquired a commanding position in the social circle to which they belong. It is only within recent years that we have come to appreciate the full importance of this principle of imitation in progressive as well as in regressive evolution. The growth of custom is but one of its applications. Bagehot was the first
