Another fundamental difference between the mental life of primitive man and that of civilized man lies in the fact that we have succeeded in developing, by the application of conscious reasoning, better systems from these crude, unconscious classifications of the sum total of our knowledge, while primitive man has not done so. The first impression gained from a study of the beliefs of primitive man is, that while the perceptions of his senses are excellent, his power of logical interpretation of perceptions seems to be deficient. I think it can be shown that the reason for this fact is not founded on any fundamental peculiarity of the mind of primitive man, but lies, rather, in the character of the traditional ideas by means of which each new perception is interpreted; in other words, in the character of the traditional ideas with which each new perception associates itself. In our own community a mass of observations and of thoughts is transmitted to the child. These thoughts are the result of careful observation and speculation of our present and of past generations; but they are transmitted to most individuals as traditional matter, much the same as folk-lore. The child associates new perceptions with this whole mass of traditional material, and interprets his observations by its means. I believe it is a mistake to assume that the interpretation made by each civilized individual is a complete logical process. We associate a phenomenon with a number of known facts, the interpretations of which are assumed as known, and we are satisfied with the reduction of a new fact to these previously known facts. For instance, if the average individual hears of the explosion of a previously unknown chemical, he is satisfied to reason that certain materials are known to have the property of exploding under proper conditions, and that consequently the unknown substance has the same quality. On the whole, I do not think that we should try to argue still further, and really try to give a full explanation of the causes of the explosion.