The universal analogy of science sanctioned Macvicar in the characteristic he thus arrived at as that of animated nature, for if inertia, or the obedience to pressures and impulses from without, be the characteristic of matter, then that which is needed as the other term to complete the couple is just what has been insisted on, viz., self-directive power, the power to cause pressures and impulses. Here is shown the symmetrical relation in which this power, when viewed as the characteristic of the whole animal kingdom (which plainly points to man, and culminates in human nature), places the animal in relation with the vegetable and the mineral kingdoms. Of minerals or crystals, the characteristic is simply self-imposing or self-concreting power. They are, so to speak, merely insoluble seeds without an embryo. To this, self-developing power is added in plants, and forms their acknowledged characteristic. While of animals the characteristic, according to the view here advanced (the same seed-producing, self-developing, powers continuing) is self-directive power superadded. This relationship between these three kingdoms of nature is as homogeneous and symmetrical as is necessary to appear to be legitimate, and is a true expression of the order of nature. Granting these two principles, the inert and the self-directive, the necessary and the free, we obtain the materials for a universe, without disputing the fact of human liberty and bringing into suspicion even the possibility either of morality or immorality. If man be really free as well as under law, in this union of body and spirit, then in human nature heaven and earth truly embrace each other; and no reason appears why, as the ages roll on, our own free thought may not have the run of the universe.... What study then can be more replete with interest, what researches can possess more of fascination, than those which Mr. Keely's discoveries are preparing the way for?