For another example we need go back only a short period in history. It is not so many years ago that dissension from accepted religious tenets was believed to be a crime. The intolerance of diverging religious views and the energy of persecution for heresy can be understood only when we recognize the violent feelings of outraged ethical principles that were aroused by this deviation from the customary line of thought. There was no question as to the logical validity of the new idea. The mind was directly agitated by the opposition to an habitual form of thought which was so deeply rooted in each individual that it had come to be an integral part of his mental life. It is important to note that in all the cases mentioned the rationalistic explanation of the opposition to a change is based on that group of concepts with which the excited emotions are intimately connected. In the case of costume, reasons are adduced why the new style is improper; in the case of heresy, proof is given that the new doctrine is an attack against eternal truth; and so with all the others. I think, however, that a close introspective analysis shows these reasons to be only attempts to interpret our feelings of displeasure; that our opposition is not by any means dictated by conscious reasoning, but primarily by the emotional effect of the new idea which creates a dissonance with the habitual. In all these cases the custom is obeyed so often and so regularly that the habitual act becomes automatic; that is to say, its performance is ordinarily not combined with any degree of consciousness. Consequently the emotional value of these actions is also very slight. It is remarkable, however, that the more automatic an action, the more difficult it is to perform the opposite action, that it requires a very strong effort to do so, and that ordinarily the opposite action is accompanied by strong feelings of displeasure. It may also be observed that to see the unusual action performed by another person excites the strongest attention, and causes feelings of displeasure. Thus it happens that when an infraction of the customary occurs, all the groups of ideas with which the action is associated are brought into consciousness. A dish of dog’s meat would bring up all the ideas of companionship; a cannibal feast, all the social principles that have become our second nature. The more automatic any series of activities or a certain form of thought has become, the greater is the conscious effort required for breaking away from the old habit of acting and thinking, and the greater also the displeasure, or at least the surprise, produced by an innovation. The antagonism against it is a reflex action accompanied by emotions not due to conscious speculation. When we become conscious of this emotional re-action, we endeavor to interpret it by a process of reasoning. This reason must necessarily be based on the ideas which rise