The theory of an atom-soul and the theory of an organizing principle must be abandoned as teleological, and so inconsistent with the facts of evolution. The theory which holds force to be a transcendental existence, a something outside of matter, must also be rejected. With the endless divisibility is given an endless motion, inward or outward; the endlessly divisible matter exists in endless motion, or what is the same, the endless motion is the endlessly divided matter. Hence motion, like matter, can never diminish; only the form of its appearance changes. The order in nature cannot be used as the basis of a teleological argument; what we call order of nature is necessity as distinguished from chance. For example, the statement that the life of the earth requires the alternation of day and night means merely that, since day and night alternate upon the earth, only such beings could arise and continue in existence thereon as flourish under this alternation. The first appearance of protoplasm introduces no strictly new thing, but only a new form of matter with life-motion; and the formation of germs is only a further step of the process. The most important characteristic of all life is sensation. This is the form in which, in all living things, that which in the rest of nature we call reaction, appears. That it is so easy for us to say in the same breath, the animal possesses sensation; and, by this particular excitation we produce in him this particular sensation, has its reason in the fact that the animal is not only capable of sensation, but is, moreover, continually in a state of sensation. By the fact of its continual reaction upon sensation, it keeps itself alive. Hence the two concepts coincide, so to speak; sensation is to life what divisibility is to matter. We express with these words more than a similitude, since all sensation is based upon motion, is, indeed, motion, and every motion may be reduced to a division or differentiation in the broadest sense of the word. All further distinctions, as, for instance, with respect to the mode of sensation (which belongs, without doubt, to plants as well as to animals), we leave unnoticed; all differences in the forms of life are but those of degree, though they may be wide differences of degree; they are to be ascribed to the influence of outer circumstances.