Just as points are the terminations of lines, lines the boundaries of surfaces, and surfaces the boundaries of portions of space of three dimensions:—so we may suppose our (essentially three-dimensional) matter to be the mere skin or boundary of an Unseen whose matter has _four_ dimensions. And, just as there is a peculiar molecular difference between the surface-film and the rest of a mass of liquid—wherever such a surface-film exists, even in the smallest air-bubble—so the matter of our present universe may be regarded as produced by mere rents or cracks in that of the Unseen. But this may itself consist of four-dimension boundaries of the five-dimensional matter of a higher Unseen, and so on. We might even try to explain by this how it is that so very little of the nature of definite description of the Unseen is given, even by a learned man like Paul—for the notion of four dimensions would have been totally unintelligible to any one eighteen hundred years ago. And just as he says he heard in the third heaven ‘unspeakable words which it is not possible for a man to utter,’ so he may have seen things which language was incompetent to describe. But on this hypothesis, as on the former, reflection leads us to the ultimate conception of an infinite series of Universes, each depending on another, and possessing of course among them an infinite store of energy.] Before concluding this article we would desire to reply to two objections which have been made to our book. It has been alleged by some that we advocate the doctrine of the past eternity of stuff or material. We therefore take this opportunity of stating that the Principle of Continuity as upheld by us has reference solely to the intellectual faculties. We are led, for instance, by this principle to assert that the process of production of the visible universe must have been of such a nature as to be comprehensible more or less to the higher intelligences of the universe. But we are not led to assert the eternity of stuff or matter, for that would denote an unauthorised application to the invisible universe of the experimental law of the conservation of matter, which belongs entirely to the present system of things. Again, it has been objected that we advocate an ethereal future state. To this we reply that our principles do not lead us to assert that the ether must play some important part in our future bodies, for our knowledge of things is vastly too limited to enable us to come to any such conclusion. 221. Let us here pause for a moment and consider the position into which science has brought us. We are led by scientific logic to an unseen, and by scientific analogy to the spirituality of this unseen. In fine, our conclusion is, that the visible universe has been developed by an intelligence resident in the Unseen.