Prejudices are stronger and more extensive among the ignorant, because the brain is so little used in any part that the clogged areas spread and thicken undisturbed for generations. The lumpy brain is transmitted in turn to the young, and the false ideas promptly reinserted during each child’s defenceless infancy, so that in time a formidable obstacle to progress is developed, called race-prejudice. The more learned are not absolutely free from prejudice, only relatively so in comparison with the more ignorant. In whatever portion of the brain we do not actively think, we find an accumulating tendency to prejudice. A healthy and active brain, used to free movement and clear connection, is affronted by any inert mass among its vital processes, as a housekeeper is affronted by some mouldy heap in a disused closet and cleans it out energetically. Old and familiar subjects are more heavily clogged in this way than those more recent and less known, yet prejudices will form, if allowed, even on the most recent of sciences. A brain, like any other organ, must be frequently and fully used to keep it healthy. These natural tendencies of the brain, the inertia of habit and the local stiffening of prejudice, would not be so injurious if left to the healthy counteracting influence of equally natural tendencies to growth. But the passive resistance has been rendered active and infinitely multiplied in power by the conscious brain action which has so mistakenly exalted its worst faculties, and choked the growth of its best ones. We very early made it the highest test of virtue to believe what we could not understand; _i. e._, to hold by main force an unassimilated idea, like a stone in the stomach; and an equal test of sin to presume to examine this irritating mass. The organic method is to relate each perception to those previously received. The brain is of its own nature logical. Impressions made upon it are sorted and stored in definite connection. This may be noted in ordinary conversation, as when the hearer discovers that the stream of talk he understood to concern Jane was really about Mary. “Oh!” says he, with a sense of physical un-ease as of one who has stepped down where there was no step, “I thought you were talking about Jane!” and there is a pause while he hastily pulls out all those statements from group “Jane” in his mind, and rearranges them in group “Mary.” By this natural power of relating impressions, called consistency, we are able to form a connected scheme of things and work rationally thereunder. If any of these impressions are incorrect, it leads to further error; and if the false impressions be those of main importance, the whole fabric of mental association will be wrong.