As the use of the natural sense of taste makes possible the choice of nourishment, and all forms of life are thus sustained, the natural taste becomes an important factor of their comfort, and upon this physical basis rests, perhaps, the whole superstructure of ethics. The first idea of ownership is doubtless found in the possession of food; and this right of property is protected by the unwritten laws of incipient life. The faculty of reason, which man has arrogated to himself, is only limited by that dim line which bounds the vital sphere and sheds its rays through all the kingdom of life, from that point where the vital spark first lights the monad, through all the labyrinths of change, to man in the full pride of his divinity, standing upon the threshold of the angelic state. It is not by the exercise of reason that water flows down hill, or that matter obeys the law of gravity; but in the exercise of autonomy, however feeble may be the motive, reason guides the act. The power of this faculty is measured by the development of others, and there is no point between the two extremes at which reason intercepts life. The degree in which all the powers of sense and faculty are developed determines the horizon of the thing which possesses them. The aggregation of powers to act constitutes life; and the aggregation of powers to guide the action constitutes reason. [Sidenote: ALL MAMMALS REASON] Leaving the realm of metaphysics and returning to the order of primates, to which we shall confine our present work, I shall resume by repeating that not only do primates have the faculty of speech, but the whole family of mammals have some form of speech which is in keeping with their conditions of life. In addition to this declaration, I assert that all mammals reason by the same means and to the same ends, but not to the same degree. The reason which controls the conduct of a man is just the same in kind as that which prompts the ape. The latter cannot carry the process to such a great extent, but _microsophic_ pedants have not shown in what respect the methods differ only in degree. That same faculty which guided man to tame the winds of commerce, taught the nautilus to lift its tentacles and embrace the passing breeze. Yet we are told that reason guides the man and instinct guides the nautilus. These are but two names for light; the one is dawn, the other noon, but both are light. I cannot see in what respect the light of a lamp differs from that of a bonfire except in volume; they are the products of the same forces in Nature, acting through the same media, and, becoming causes, produce the same effects. That psychic spark which dimly glows in the animal bursts into a blaze of effulgence in man. The one differs from the other just as a single ray of sunlight differs from the glaring light of noon. [Sidenote: EFFECTS OF ONE GREAT CAUSE] If man could disabuse his mind of that contempt for things below his plane of life,