The human body, like other organisms, forms itself out of the semi-fluid[colloidal] state. However for its formation a constant supply of gaseous material is necessary. The most important is the oxygen transmitted by breathing.
We may consider in the first place a solid constituent of the body, e.g., a bony structure. It is precipitated from semi-fluid material. In this separation the ego-organization is active. Anyone may convince himself of this who studies the formation of the bony system. For, in the embryonic period and in childhood, the bony system develops in the same measure in which the human being receives his human form and figure, the characteristic expression of the ego-organization. The transformation of protein which underlies this process first separates the (astral and etheric) foreign forces from the protein; the protein then passes through the inorganic state, and in so doing, has to become fluid. In this condition, the ego-organization, working in the element of warmth, takes hold of it and introduces it to man's own etheric body. It thus becomes human protein, but it still has a long way to go before the transformation into bony substance is achieved.
After its transformation into human protein, it must first be prepared for the receiving and transforming of calcium carbonate, calcium phosphate and the like. To this end it must undergo an intermediate stage. It must come under the influence of the absorption of gaseous substance. This brings into the protein the transformation-products of carbohydrates. The substances which thus arise can provide a basis for the form of the individual organs. They do not represent the finished substances of the organs, e.g. liver or bone-substance, but a more general, less differentiated substance, out of which the individual organs of the body can then be built up. It is the ego-organization which is active in moulding the final shape of the organs. The astral body is active in the above-mentioned undifferentiated organic substance. In the animal, this astral body also takes upon itself the task of moulding the final form of the organs; in man, the activity of the astral body and, with it the animal nature as such, persists only as a general underlying foundation for the ego-organization. In man the animal development is not carried to a conclusion; it is interrupted in its path and humanity is imposed, as it were, by the ego-organization upon it.
Now the ego-organization lives entirely in states of warmth. It derives the individual organs from the undifferentiated astral nature. It works upon the undifferentiated substance with which the astral nature provides it, by enhancing or lowering the states of warmth of the nascent organs.
If the ego-organization lowers the state of warmth, inorganic materials enter the substance and a hardening process sets in; the basis is provided for the formation of the bones. Salt-like substances are absorbed.
If on the other hand the ego-organization enhances the state of warmth, organs are formed whose action is to dissolve the organic substance, leading it over into a liquid or gaseous condition.
Let us assume, the ego-organization finds insufficient warmth developed in the organism, for the adequate enhancement of the warmth-conditions in those organs which require it. Organs whose proper functioning lies in the direction of a dissolving process will then fall into a hardening activity. They assume in a pathological way the tendency which in the bones is healthy
Now the bone, once it has been formed, is an organ which the ego-organization releases from its domain. It enters a condition where it is no longer taken hold of by the ego organization inwardly, but only in an outward way. It is removed from the domain of growing and organizing processes, and serves the ego in a merely mechanical capacity, carrying out the movements of the body. Only a remainder of the inner activity of the ego-organization continues to permeate it throughout life because the bony system must, after all, remain as an integral organic part within the organism; it must not be allowed to fall entirely out of the sphere of life.
The arteries are the organs which for the reason above mentioned, may pass into a formative activity similar to that of the bones. We then have the calcifying disease of the arteries known as sclerosis. The ego-organization is, in a certain sense, driven out of these organ-systems
The opposite is the case when the ego-organization fails to achieve that lowering of the state of warmth which is needed for the region of the bones. The bones then assume a condition similar to those organs which normally unfold a dissolving kind of activity. Owing to the deficient hardening process, they are no longer able to provide a basis for the incorporation of salts. Thus the final process in the development of the bone-formations, which properly belongs to the organizing domain of the ego, fails to take place. The astral activity is not arrested at the proper point on its path. Tendencies towards malformation of shape must then appear; for the healthy creation of the human form and figure is only possible within the realm of the ego-organization.
We have here the ricketic diseases. From all this it becomes evident how the human organs are connected in their activities. The bone comes into being in the realm of the ego-organization. It still continues to serve it even when the actual formation is concluded, when the ego-organization no longer forms and creates the bone, but uses it for voluntary movements. It is the same for that which arises in the domain of the astral organization. Undifferentiated substances and forces are there engendered. These occur throughout the body as an underlying basis for the differentiated organ forming processes. The astral activity carries them up to a certain stage and then makes use of them. The entire human organism is permeated by semi-fluid material, in which an astrally directed activity holds sway.
This activity spreads itself in the secretions which are made use of to form the organism in the direction of its higher members. Secretions tending in this direction are to be seen in the products of the glands which play so important a part in the economy of the organism and its functions. In addition to these inward secretions, we then have the processes that are excretions in the proper sense, towards the outer world. But we make a mistake if we regard the excreta merely as those portions of the food consumed which the organism cannot make use of and therefore discards. For the important thing is not the mere fact that the organism throws certain substances out, but rather, that it goes through the activities which result in the excretions. The exercise of these activities is something that the organism needs for its subsistence. This activity is just as necessary as that by which the substances are received into the organism, or deposited internally. In the healthy relationship of both activities, there lies the very essence of organic life and action.
Thus, in the outward excretions we see the result of astrally orientated activity. And if the excreta contain substances which have been carried as far as the inorganic nature, then the ego-organization, too, is expressing itself in them. Indeed, this part of the ego-organization's life is of particular importance. For the force that is spent on such excretions creates, as it were, an inward counter-pressure. And this latter is a necessary factor for the healthy existence of the organism. Thus the uric acid, which is secreted through the urine, creates as an inward reaction the correct tendency of the organism to sleep. Too little uric acid in the urine and too much in the blood will give rise to so little sleep that it is insufficient for the health of the organism.