The scientific study of spirit consists in following up intelligently and according to definite method the same principle that now only flashes upon us at intervals fitfully and vaguely. When we once realise that this universal and unlimited power of spirit is at the root of all things and of ourselves also, then we have obtained the key to the whole position; and, however far we may carry our studies in spiritual science, we shall nowhere find anything else but particular developments of this one universal principle. "The Kingdom of Heaven is _within_ you." III I have laid stress on the fact that the "innermost within" of all things is living Spirit, and that the Science of Spirit is distinguished from the Science of Matter in that it contemplates Energy under an aspect of responsive intelligence which does not fall within the scope of physical science, as such. These are the two great points to lay hold of if we would retain a clear idea of Spiritual Science, and not be misled by arguments drawn from the physical side of Science only--the livingness of the originating principle which is at the heart of all things, and its intelligent and responsive nature. Its livingness is patent to our observation, at any rate from the point where we recognise it in the vegetable kingdom; but its intelligence and responsiveness are not, perhaps, at once so obvious. Nevertheless, a little thought will soon lead us to recognise this also. No one can deny that there is an intelligent order throughout all nature, for it requires the highest intelligence of our most highly-trained minds to follow the steps of this universal intelligence which is always in advance of them. The more deeply we investigate the world we live in, the more clear it must become to us that all our science is the translation into words or numerical symbols of that order which already exists. If the clear statement of this existing order is the highest that the human intellect can reach, this surely argues a corresponding intelligence in the power which gives rise to this great sequence of order and interrelation, so as to constitute one harmonious whole. Now, unless we fall back on the idea of a workman working upon material external to himself--in which case we have to explain the phenomenon of the workman--the only conception we can form of this power is that it is the Living Spirit inherent in the heart of every atom, giving it outward form and definition, and becoming in it those intrinsic polarities which constitute its characteristic nature.