This view of the eugenic superiority of the successful class, in conjunction with the smallness of the families in this class, has led to pessimistic views regarding the future of the race. Some writers hold that civilization necessarily exhausts a stock, that such exhaustion has been the main cause of the decay of great nations in the past, and that the process was never so rapid as in our own time. Others think that, although the decline is real, it has not yet gone very far, and that we may be saved from it by a rational eugenics. The argument that civilization, especially modern civilization, tends to race deterioration is simple and, to say the least, plausible. Civilization selects the best stocks and uses them up. The ablest types of men, incited by ambition, achieve success and carry on the more intellectual and exhausting functions of the social order. At the same time their success subjects them to the upper-class conditions of luxury and exacting ideals. The result is infecundity of the successful class, and of the superior stocks which it represents. The best grain is eaten and the next crop raised from inferior seed. This process may be peculiarly rapid in a democracy like ours, because it is our tendency, and indeed our ideal, to make the rise of natural ability as free and rapid as possible. When life in general was traditional, functions inherited or customary, and opportunity confined to a few, the process by which natural ability rose to the top and evaporated was slow and uncertain. But now, with our universal spurring of ambition, our racial resources are rapidly spent, and, short of a change in the ideals and way of life of the successful class, it is not apparent how they can be saved.[57] The opinion upon which all this depends, that the successful class represents the best stocks, is, however, open to question. One criticism of it is that opportunity and success are still mainly a matter of privilege rather than of natural ability; and many assert that in spite of our ideal of equal opportunity the ascendancy of privilege is increasing, and that nothing short of a revolution can overthrow it. If this view is at all correct it undermines the whole idea that the present successful class represents an aristocracy of natural ability, or has especial eugenic significance of any kind. It is worth noting, however, that one may allow much present dominance of privilege, but hold that, in spite of it, there is a continuous flow of able stocks toward the top, so that the upper strata probably have a considerable eugenic superiority. And if we believe that improvements in education are increasing opportunity as against privilege, this superiority should be growing. In that case it would be a great object to insure fecundity in these strata.