Once the era of civilization is inaugurated, power depends on moral capacity, that is, the capacity to protect and promote a considerable number of interests, and thus win their backing. This is proved in every field of human activity, military, political, religious, intellectual, social, or commercial. Commerce and industry afford at present the most striking examples. The man who succeeds is the man who can satisfy the greatest number of appetites. And the more his enterprise grows the more it becomes a public concern; {138} and the more, therefore, must he be studious of public welfare and responsive to public opinion. Thus manufacturing, transportation, or banking, when conducted on a large scale, touch life at so many points, that he who seeks to gain power or wealth by means of them will gradually and without any abrupt change of motive approximate the method of disinterested service. So every station in life, from that of the ruler to that of the shopkeeper, has its own characteristic form of the one problem of _meeting, adjusting and fulfilling interests_. The desire to be successful or to attain eminence in one's station exerts a constant pressure in the direction of the invention, trial, and selection of methods that will solve this problem. And such methods once devised are at once supported by the interests they serve, and become necessary to the life of the community. Now the wise leader anticipates the needs and wishes of his followers, and so enjoys their continued support without ever seeming to depend on it. But there are very few such wise leaders. The reason for their scarcity lies in the natural inertia of profitable activities. There is a universal propensity to let well enough alone. So methods are allowed to outlive their usefulness, or remain unmodified when more provident and fruitful methods could be devised. When leadership {139} thus fails to be statesmanlike and far-sighted, there occurs that uprising of the disaffected interests which is called _revolution_.