This picture of the threefold psycho-physical structure of man will now enable us to understand the evolution of consciousness both in individual life and in the life of mankind. To furnish the foundation of waking consciousness, parts of the body must become divorced from life. This process, however, is one which, if we take the word in its widest sense, we may call, ageing. All organic bodies, and equally that of man, are originally traversed throughout by life. Only gradually certain parts of such an organism become precipitated, as it were, from the general organic structure, and they do so increasingly towards the end of that organism's life-span.