Dr, Steiner, however, indicates that the assimilatory processes of the digestive system are the direct and immediate physical basis of volition, just as the neural processes are the basis of ideation. We are, of course, totally unconscious of the processes of digestion and blood formation, of the whole anabolic or constructive activity of assimilation. The digestive system, on the other hand, assimilates, transforms, and incorporates the ponderable materials. The characteristic processes of the upper man, the man of nerves and senses, are thus altogether different from those of the lower or digestive man. Between them is the rhythmic system, on whose processes the life of feeling is based.
Feeling is based on the rhythmic processes of breathing and the circulation of the blood.
Thus, each of the three systems is subject to its own distinct and peculiar laws. It is a unity which does not exist once and for all, but which is being brought about all the time. The lower organism assimilates and works up the materials of nourishment, and the nourishing juices thus formed are met by the air which is absorbed from outside through the activities of the upper organism. Thus there arises an interplay of liquid and airy currents, and the activity of the heart is a consequence of this mutual interaction of the two systems. This is true, even in the mechanical sense.