The idea that man and wife together first constitute the complete human being, and that the real future of this human being lies in the children--the idea of the family is, certainly, of all ideas, primordial, though it probably came late to consciousness. From the family developed the tribe with the eldest at its head. The more peaceful the tribe, the more others combined against it, and by their combination compelled it still further to strengthen its resources. The feeling of power awakened by the growing concord extended further and further, and finally made its way to the individual with the full force of the Idea. This development, but more especially the compelling power of the struggle for existence, soon called the bravest to command in place of the eldest of the tribe. It is by the agency of no other being that, in the mutual relation of physical and mental activity, consciousness is attained; man himself comes to a feeling of himself. In the being endowed with soul, who on the one hand attains, through integration, an independence that appears as the impulse to self-preservation, on the other hand becomes conscious of this impulse to self-preservation through a centralized nervous system that raises the part-sensations to feelings of the whole, sensation divides into two chief functions, which appear as passion and thought. We are not concerned, in thought and passion, with opposites, but with an opposition which a single phenomenon develops through manifold action and reaction with the rest of the world of phenomena. The distinction is merely a convenience in finer investigations; there is, in fact, as little thought without emotion as emotion without thought. And since emotion always manifests itself as will, this highest opposition is best defined as that of thought and will. In order to understand the human being, we must analyze these two sides of consciousness.