SOPHEREUS. I have been reading a good deal, but I have reflected more. I may not be able to reconcile the metaphysical speculations of the different schools of philosophy by explanations that will satisfy others, but I can satisfy myself on one point. This is, that power, force, energy, causation, are all attributes of mind, and can exist in a mind only. Let us pass for a moment from abstract reasoning to an illustration drawn from familiar objects. A ton of coal contains a certain amount of what is scientifically called energy. This energy becomes developed by combustion, which liberates heat. The heat, when applied to water, converts the water into a vapor called steam--a highly elastic substance. The expansion of the steam against a mechanical instrument called a piston produces motion, and an engine is driven. The force thus obtained represents the energy that was latent in the coal. If we inquire whence the coal obtained this latent energy, there is a hypothesis which assigns its origin to the sun, which laid up a certain quantity of it in the vegetable substances that became converted into coal in one of the geological periods of the earth's formation. But in order to find the ultimate and original cause--the _causa causans_ of the whole process--we must go behind the steam and its expansive quality, behind the heat which converts the water into steam, behind the coal and its combustible quality, and behind the sun and its indwelling heat, a portion of which was imparted to and left latent in the vegetable substances that became coal. We must inquire whence they all originated. If they did not create themselves--an inconceivable and inadmissible hypothesis--they must have originated in some creating power, which commanded them to exist and established their connections. Without a mental energy and its exertions, matter and all its properties, substance and all its qualities, the sun's indwelling heat and its capacity to be stored up in vegetable fiber in a latent condition, could not have existed, and the forces of nature of which we avail ourselves would never have emerged from the non-existent state that we conceive of as "chaos." I know very well that we are accustomed to associate with inanimate matter the ideas of power, force, energy, and causation. But if we rest in the conception of these as acting of themselves, and without being under the control of an originating mind or a determining will, we may think that we have arrived at ultimate causes, but we have not. We have arrived at subsidiary causes--the instruments, so to speak, in the control of an intellect which has ordained and uses them. Whether we look at the physical causes by which the early Greek philosophers endeavored to explain the phenomena of the universe, or at one of Plato's conceptions of a designing and volitional agency in the formation of the Kosmos, or to another of his conceptions, the sovereignty of universal ideas