This continent or vehicle of the mind is the human body. The body has two aspects,--substance and form, answering to the two aspects of the mind,--affection and thought: and affection finds its incarnation or correspondence in substance; and thought, in form. The mind, in short, realizes itself in terms of its reflection in the body, much as the body realizes itself in terms of its reflection in the looking-glass: but it does more than this, for it identifies itself with this its image. And how is this identification made possible? It is brought about by the deception of sense, which is the medium of communication between the spiritual and the material man. Until this miraculous medium is put in action, there can be no conscious relation between these two planes, admirably as they are adapted to each other. Sense is spiritual on one side and material on the other: but it is only on the material side that it gathers its reports: on the spiritual side it only delivers them. Every one of the five messengers whereby we are apprised of external existence brings us an earthly message only. And since these messengers act spontaneously, and since the mind's only other source of knowledge is intuition, which cannot be sensuously confirmed,--it is little wonder if man has inclined to the persuasion that what is highest in him is but an attribute of what is lowest, and that when the body dies, the soul must follow it into nothingness. Creative energy, being infinite, passes through the world of causes to the world of effects--through the spiritual to the physical plane. Matter is therefore the symbol of the ultimate of creative activity; it is the negative of God. As God is infinite, matter is finite; as He is life, it is death; as He is real, it is unreal; as He reveals, matter veils. And as the relation of God to man's spirit is constant and eternal, so is the physical quality of matter fixed and permanent. Now, in order to arrive at a comprehension of what matter is in itself, let us descend from the general to the specific, and investigate the philosophical elements of a pebble, for instance. A pebble is two things: it is a mineral: and it is a particular concrete example of mineral. In its mineral aspect, it is out of space and time, and is--not a fact, but--a truth; a perception of the mind. In so far as it is mineral, therefore, it has no relation to sense, but only to thought: and on the other hand, in so far as it is a particular concrete pebble, it is cognizable by sense but not by thought; for what is in sense is out of thought: the one supersedes the other. But if sense thus absorbs matter, so as to be philosophically indistinguishable from it, we are constrained to identify matter with our sensuous perception of it: and if our exemplary pebble had nothing but its material quality to depend upon, it would cease to exist not only to thought, but to sense likewise. Its metaphysical aspect, in short, is the only reality appertaining to it.