The cells of the individuals in an organism are consequently at once building-material and builders, and in their latter capacity are endowed with wants and aspirations that with natural necessity force them to organization without conscious plan or purpose. Necessity is the teacher that tells them how to organize. Some speak of a social instinct that man does or should possess; but its existence has never been shown. On the contrary, it is only by those needs that can only be satisfied by a community that men are driven to unite socially. Similarly with the cells. Only by building up an organism are they able to satisfy their common wants. What society is to human individuals, the natural organism is to the cells. No trade or industry can be found in the state that does not serve to provide for some common want of the people, and no tissue nor organ exists in the natural organism but for satisfying collective needs of the cells. These collective needs are at the same time the higher needs of the individuals. The organism provides the power that the isolated individual does not possess. Organization allows that specializing of effort which so essentially contributes to the productivity of labor. The more limited the operations each individual has to perform, the more rapidly and perfectly are they done. Although the cell lives in a world inaccessible to our immediate comprehension, we still possess means to ascertain that it has the same fundamental qualities as man. We observe manifestations of life in the cell corresponding to those of sensitivity, feeling and will-power in man. The cell’s comprehending faculty has been termed irritability and its power of action spontaneity. From certain physiological phenomena the conclusion has also been drawn that the cell likewise possesses memory. CHAPTER X. The Organic Relationship Between the Soul and the Cells. Hitherto only little study has been given to the spiritual qualities of the cells, and such investigations must always meet with certain insurmountable difficulties. The reason is that we only judge others by ourselves and we are therefore unable to understand the spiritual life of any being that is not one of our kin. If a being stands higher or lower than ourselves its spiritual experiences, if not entirely different from ours, are at least limited and modified by the being’s own power of comprehension. If, however, these beings show manifestations of life that we understand, we must conclude that their spiritual or mental life is correspondingly active.