And here the very context suggests naturally the consideration of the last of the three steps which, following the course marked out for it by God, the human mind has at last made in very modern times toward a true physical science, and a right understanding of the most inmost secrets of nature. It consists in a closer observation and a commencing recognition of a sacred thread of ensouled life--of an internal soul-like link which holds together the whole frame of nature. The thing and force itself are as old as the world and every sphere of existence--all the leaves of tradition and history are full of its manifestations and effects. But the methodical observation and treatment of these phenomena (in which alone the true scientific character consists) dates its commencement within little more than half a century ago. To speak, therefore, agreeably to the measure of time in the slow development of science, it is of yesterday or the day before; and it is even on this account also that I have been constrained to count this third and last advance toward a higher science of nature, as nothing more than a half-step. For it is only a beginning which as yet has gained no firm footing in the minds of men, and, moreover, besides the right and direct road, it has already opened many by-paths of possible error. This only direct road, that higher standard of correct judgment which at the very commencement we alluded to as the guiding rule in these matters, must be sought by philosophy in that divine sword of the Spirit which pierces even to the marrow of life, dividing soul and spirit, and which also is a discerner of spirits. But, if another standard and a higher tribunal is to be set up, then I must leave it to others who, perhaps, know more about the matter than I do, and are better qualified to decide upon it. This spiritual warfare, at any rate, can not be much longer eluded or avoided. O that men would take therein Holy Writ exclusively for their guide! For it, indeed, regards the whole of life, and every important moment of it, as a conflict with invisible powers; as also it tacitly implies, or expressly intimates that the whole sensible world is to be looked upon as nothing else than an almost transparent, and, at all events, a very perishable veil of the spiritual world. To the leader of the rebel spirits the Bible ascribes so great an influence in creation, that it calls him the prince, nay, even the god of this world--the ruler of its principalities and powers. And in order that this might not be taken in a mere figurative sense, and be understood only of a race of men morally corrupt and depraved, these spiritual potentates are in other places expressly called the elementary powers of nature--powers of the air, which in this dark planetary world of ours is compounded of light and darkness, and ever struggling between life and death. The true key and explanation of the whole may, however,