It is important to identify the law of human progress. According to Herbert Spencer, civilization is “progress from an indefinite, incoherent homogeneity to a definite coherent heterogeneity” (476). A typical explanation of the civilizational differences is rooted in “difference in capacity”—for instance, the difference between intelligence and ingenuity and ignorance and laziness (476). In this framework, “the civilized races are the superior races” (476). Civilizational progress arises in a world that is “the struggle for existence,” and people are pushed “to new efforts and inventions” (477).

However, this theory of progress does not explain the “fixed, petrified civilizations” around the world (479). For instance, both the inhabitants of the Indian subcontinent and China were far more advanced when the Europeans “were savages” (480). Then, however, their progress seems to have stopped (480). Every civilization has a period of growth, stagnation, and decline as a “universal rule” (482). The cyclical rise and fall of civilizations means that “hard-won progress has been lost to the race forever” (484). In this way, new civilizations arise, triumph, and then fall: “It is the barbarians of the one epoch who have been the civilized men of the next” (484). It appears that “the conditions produced by the growth of civilization itself” contain the reason for its decline (486).