Only in man does the ego-principle enter as an individual entity into the single physico-etheric-astral organism. Here, however, the succession of stages we have outlined comes to a conclusion. For with the appearance of the I as an individual principle, the preceding evolutionary process - or, more correctly, the involutionary process - begins to be reversed. In moving up from one kingdom to the next, we find always one more dynamic principle appearing in a state of separation from its mother-sphere; this continues to the point where the I, through uniting itself with a thus emancipated physico-etheric-astral organism, arrives at the stage of self-consciousness. Once this stage has been reached, however, it falls to the I to reverse the process of isolation, temporarily sanctioned by the cosmos for the sake of man.