The life of animals is developed by a process exactly the reverse of vegetable life. It is maintained by the destruction of the compounds which the vegetable had formed. These compounds are taken into the body as food, and after undergoing certain modifications and arrangements are finally decomposed. Of the force thus set free a part makes its appearance as heat, maintaining an even temperature in the body, and another part supplies the power by virtue of which the muscles, &c., act. No manifestation of animal life is possible except by force thus set free. It seems all but certain that we cannot think a single thought without the decomposition of an equivalent amount of the brain. It must not, however, be concluded that force and life are identical. Force seems to be only the instrument of which the higher principle of life makes use in its manifestations. Force then pervades the whole universe so far as it is cognizable by our senses. But we cannot conceive of force as acting, without at the same time conceiving of something on which that force acts. That something, whatever it may be, we designate "matter." We have not the slightest idea of what matter really is--no man has ever yet succeeded in separating it from its combination with force. Even if success were possible, which seems very improbable, it is not likely that matter by itself would be discernible by any of our senses. We know that two of them, sight and hearing, enable us to perceive certain kinds of motion, i. e. manifestations of force, and this is in all probability the case with the rest of them. The existence of matter then is not known by scientific proof but by inference. Our belief in it arises from something in the constitution of our minds which makes it a necessary inference. There is one more point in reference to force which must be noticed. It is indestructible, but it is capable of what is termed "degradation." It may exist in various intensities and quantities, and a small quantity of force of a higher intensity may be changed into a larger quantity of force at a lower intensity. In the instance above given of the union of oxygen and hydrogen, heat is given out, but heat does not suffice to dissolve that union. The force must be supplied in the more intense form of Voltaic Electricity. But to reverse this process seems impossible for us. As, however, this is clearly explained in a previous volume of this series, [Footnote: Can we Believe in Miracles? p. 152.] it is not necessary to dwell upon it at length. We may conclude then that the whole material universe is built up of matter and force in various combinations, but we can form no conception of what these two things are in themselves; they are only known to us by the effects produced by their union in various proportions. SECTION 3. THE BEGINNING. "In the beginning God created the heaven and the earth. "And the earth was desolate and void, and darkness upon the face of the deep."