XVIII. Purifying the Blood by Removing Egoism through the Mystery of Golgotha, an Easter Lecture

You also have to understand that something else was connected with this way of breathing air, with the spirit coming down into the human form. It was closely bound up with what we call the warm blood of man, or rather blood that was warmer than the surroundings. Before this moment in time had come in earth evolution, there were no warm-blooded life forms. Warm-blooded animals only came into existence at a later stage. This breathing was therefore connected with warm-bloodedness, and this meant that something else also happened then. A certain quantity, a certain amount of warmth entered into the human being, the blood warmth you still have today. This is a higher kind of warmth than the warmth in the world around you. In those days, at the time that preceded this actual time when man came into being, something was present in the environment of our ancestors that was very different from the spirit embodied in the air.