212. As regards the form of heaven specifically and how it moves and flows, this not even the angels of heaven can comprehend. Some idea of it can be presented by the form of all things in the human body when examined and investigated by an acute and wise observer. For it has been shown above in their relevant sections that the entire heaven resembles one man (see n. 59-72), and that all things in man correspond to the heavens (n. 87-102). How incomprehensible and inexplicable that form is, may appear in a general way only from the nerve fibres by which each part and all parts of the body are joined together. What these fibres are and how they proceed and flow in the brain, not even the eye can perceive, for innumerable fibres are there so interwoven, that, taken together, they appear as a soft continuous mass; and yet, it is in accordance with these that each thing and all things of the will and the understanding flow most distinctly into acts. Again, how these fibres join together in the body is clear from the various plexuses, such as those of the heart, the mesentery and others, and also from the knots called ganglions, into which many fibres from every region enter and there intermingle, and when joined together in another way, go forth to their functions and this again and again; besides similar things in every viscus, member, organ and muscle. Whoever examines with the eye of wisdom these fibres and their many wonders will be utterly bewildered. Yet the things seen with the eye are few. Those not seen are still more wonderful because they belong to an inner realm of nature. That this form corresponds to the form of heaven is clearly evident from the working of everything of the understanding and of the will within it and in accordance with it. For whatever a man wills passes spontaneously into an accordant act, and whatever he thinks spreads through the fibres from their beginnings even to their terminations from which the senses are derived; and because it is the form of thought and will, it is the form of intelligence and wisdom. This is the form that corresponds to the form of heaven. From this it can be known that such is the form in accordance with which every affection and thought of the angels extends forth, and that so far as the angels are in that form, they are in intelligence and wisdom. That this form of heaven is from the Divine Human of the Lord may be seen above (n. 78-86). These things have been stated to make it known also that the heavenly form is such that, even as to generals, it can never be completely expressed, so that it is incomprehensible even to the angels, as has been said above.