The whole of outside nature has been built up out of what has been thrust forth from the human being

Rudolf Steiner: "We need to realise that everything around us in the wide world of the macrocosm has a relationship with our complicated inner world of the microcosm, and every kind of food there is has a definite connection with what is within our organism. We have heard often enough that man has passed through a long evolution, and how the whole of outside nature has been built up out of what has been thrust forth from man. Time and again in our studies we have gone back to the ancient Saturn period, where we found that there was nothing in existence apart from man, who, as it were, thrust forth the other kingdoms of nature: the plants, the animals, and so on. In that evolution man built up his organs in accordance with what they thrust forth. Even when the mineral kingdom was pushed out, certain specific inner organs arose. The heart could not have arisen if certain plants, minerals and mineral possibilities had not arisen externally in the course of time. Now what arose externally has a certain connection with what arose within. And only the person who knows of this connection can prescribe in individual cases how the macrocosmic element outside can be used in the microcosm, otherwise man will experience in a certain way that he is taking in something that is not right for him. So we have to turn to spiritual science for the actual basis of our judgment. It is always superficial to follow purely external laws taken from statistics or chemistry when prescribing dietary treatment. We need quite a different basis, for spiritual knowledge has to be active when we deal with man in health or sickness."

Source: November 10, 1908. GA 107