Lecture I

Valid sciences of human physiology and biology will only be possible when the whole human body and each of its separate organs, such as heart, lungs, liver, are seen to encompass polar opposites which incline them on the one hand towards dissolution into warmth and, on the other hand, towards consolidation into the mineral state. The way the organs function will only be properly understood once the whole human being, as well as each separate organ, are seen in this light. The science of human health and sickness will only find a footing on healthy ground once these polarities in the physical human being are able to be seen everywhere. Then it will be known, for instance, that at the change of teeth, around the seventh year, ahrimanic forces are setting to work in the head region; or that when the physical body starts to develop towards the warmth pole at puberty, this means that luciferic forces are at work; that in the rhythmical nature of the human being there are constant swings of the pendulum, physically too, between the luciferic and the ahrimanic aspect. Until we learn to speak thus, without any superstition, but with scientific exactness, about the luciferic and ahrimanic influences upon human nature—just as today we speak without superstition or mysticism about positive and negative magnetism, about positive and negative electricity, about light and darkness—we shall not be in a position to gain knowledge of the human being which can stand up to the abstract knowledge of inorganic nature that we have achieved during the course of recent centuries.