212. When it comes to the particulars of the form of heaven and how it proceeds and flows, this not even the angels can comprehend. Some conception of it can be gained from the form of all things in the human body, when this is scanned and investigated by an acute and wise man; for it has been shown above, in their respective chapters, that the entire heaven reflects a single 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 is evident only in a general way from the nervous fibers, by which each part and all parts of the body are woven together. What these fibers are, and how they proceed and flow in the brain, the eye cannot at all perceive; for innumerable fibers are there so interwoven that taken together they appear like a soft continuous mass; and yet it is in accord with these that each thing and all things of the will and understanding flow with the utmost distinctness into acts. How again they interweave themselves 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 fibers enter from every region and there intermingle, and when variously joined together go forth to their functions, and this again and again; besides like things in every viscus, member, organ, and muscle. Whoever examines these fibers and their many wonders with the eye of wisdom will be utterly bewildered. And yet the things seen with the eye are few, and those not seen are still more wonderful because they belong to an inner realm of nature. It is clearly evident that this form corresponds to the form of heaven, because all the workings of the understanding and the will are within it and are in accordance with it; for it is in accordance with this form that whatever a man wills passes spontaneously into act, and whatever he thinks spreads through the fibers from their beginnings even to their terminations, which is the source of sensations; and inasmuch as it is the form of thought and will, it is the form of intelligence and wisdom. Such is the form that corresponds to the form of heaven. And from this it can be known that such is the form in accordance with which every affection and thought of angels extends itself, 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 can be seen above (n. 78-86). All this has been said to make clear also that the heavenly form is such that even as to its generals it can never be completely known, thus that it is incomprehensible even to the angels, as has been said above.