The study of the material world is not Materialism, if it be allowed to progress to its legitimate issue. Materialism is that limited view of the universe which will not admit the existence of anything but mechanical effects of mechanical causes, and a system which recognises no higher power than the physical forces of nature must logically result in having no higher ultimate appeal than to physical force or to fraud as its alternative. I speak, of course, of the tendency of the system, not of the morality of individuals, who are often very far in advance of the systems they profess. But as we would avoid the propagation of a mode of thought whose effects history shows only too plainly, whether in the Italy of the Borgias, or the France of the First Revolution, or the Commune of the Franco-Prussian War, we should set ourselves to study that inner and spiritual aspect of things which is the basis of a system whose logical results are truth and love instead of perfidy and violence. Some of us, doubtless, have often wondered why the Heavenly Jerusalem is described in the Book of Revelations as a cube; "the length and the breadth and the height of it are equal." This is because the cube is the figure of perfect stability, and thus represents Truth, which can never be overthrown. Turn it on what side you will, it still remains the perfect cube, always standing upright; you cannot upset it. This figure, then, represents the manifestation in concrete solidity of that central life-giving energy, which is not itself any one plane but generates all planes, the planes of the above and of the below and of all four sides. But it is at the same time a city, a place of habitation; and this is because that which is "the within" is Living Spirit, which has its dwelling there. As one plane of the cube implies all the other planes and also "the within," so any plane of manifestation implies the others and also that "within" which generates them all. Now, if we would make any progress in the spiritual side of science--and _every_ department of science has its spiritual side--we must always keep our minds fixed upon this "innermost within" which contains the potential of all outward manifestation, the "fourth dimension" which generates the cube; and our common forms of speech show how intuitively we do this. We speak of the spirit in which an act is done, of entering into the spirit of a game, of the spirit of the time, and so on. Everywhere our intuition points out the spirit as the true essence of things; and it is only when we commence arguing about them from without, instead of from within, that our true perception of their nature is lost.