6. Tree of Knowledge II

What the ordinary materialistic physiologist studies by way of our head, my dear friends, is naturally not the thought in the astral body, nor the thought motion in the etheric body, but it is in reality the hollow head. And the reason why one cannot penetrate into this hollow space is because one can only advance as far as the real extends and there one comes up against the hollow space. So one cannot enter the hollow spaces. It is exactly as if you picture a column of Seltzer-water and there are bubbles of air in it: the thinner elements appear to the being who lives in the denser element as frightfully hard. So too we cannot penetrate into the actual hollow spaces, but only because there is nothing there, because it is a hollow. Thus if one would draw the human head occultly, one must not draw it so, but in the negative, and what remains inside as empty, that would be the human being (see diagram p.l2a). This means that where the painter generally lays on the colours and thinks he is painting man, he ought really to leave it empty: then one would be painting spiritually-realistically, for otherwise one paints where there is nothing and leaves free the part where there is something.