Carbono, silício e cálcio em Steiner (2007)

Now we find limestone and silicon as the basis of plant growth too. Our need is to gain a knowledge of what the carbon develops throughout the process of digestion, breathing and circulation in man — in relation to the bony structure and the silicious structure. We must somehow evolve a knowledge of what is going on in there — inside the human being. We should be able to see it all, if we could somehow creep inside. We should see the carbonaceous formative activity raying out from the circulatory process into the calcium and silicon in man. (Steiner 2007:27)

STEINER, Rudolf. 2007. The Agriculture Course. (Trans.: George Adams) Shrewsbury: Wilding & Son Ltd.