Each generation has its fixed ideas. A few are inherited intact by the generation that follows, a few are passed on with slight transformation, but most crumble or change into different versions of the old half-truths. Among the most enduring of prejudices is the fallacy of the good old times. Upon that formula nine-tenths of the successful historical romances are built. That American wives suffer from foreign husbands, that capital is ruthless, that youth is right and age wrong, that energy wins over intellect, that virtue is always rewarded, are American conceptions of some endurance that have given short but lofty flights to thousands of native stories. More important, however, in the history of fiction are those wide and slow moving currents of opinion, for which prejudice is perhaps too narrow a name, which flow so imperceptibly through the minds of a generation or a whole century that there is little realization of their novelty. Such a slow-moving current was the humanitarianism which found such vigorous expression in Dickens, the belief in industrial democracy which is being picked up as a theme by novelist after novelist to-day, or the sense of the value of personality and human experience which so intensely characterizes the literature of the early Renaissance. If a novel draws up into itself one of these ideas, filling it with emotion, it gains perhaps its greatest assurance of immediate popularity. If the idea is of vast social importance, this popularity may continue. But if it is born of immediate circumstance, like the hatred of slavery in "Uncle Tom's Cabin," or if it is still more transient, say, the novelty of a new invention, like the airplane or wireless, then the book grows stale with its theme. The like is true of a story that teaches a lesson a generation are willing to be taught--it lives as long as the lesson. What has become of Charles Kingsley's novels, of the apologues of Maria Edgeworth? "Main Street" is such a story; so was "Mr. Britling Sees It Through"; so probably "A Doll's House." Decay is already at their hearts. Only the student knows how many like tales that preached fierily a text for the times have died in the past. But I am writing of popularity not of permanence. In four popular novels out of five, even in those where the appeal to the instinctive emotions is dominant, suspect some prejudice of the times embodied and usually exploited. It is the most potent of lures for that ever increasing public which has partly trained intelligence as well as emotions.