Complexes are psychic contents which are outside the control of the conscious mind. They have been split off from consciousness and lead a separate existence in the unconscious, being at all times ready to hinder or to reinforce the conscious intentions.

Dream analysis stands or falls with [the hypothesis of the unconscious]. Without it the dream appears to be merely a freak of nature, a meaningless conglomerate of memory-fragments left over from the happenings of the day.

I can still recall vividly how Freud said to me, 'My dear Jung, promise me never to abandon the sexual theory. That is the most essential thing of all. You see, we must make a dogma of it, an unshakable bulwark' ... In some astonishment I asked him, 'A bulwark-against what?' To which he replied, 'Against the black tide of mud'—and here he hesitated for a moment, then added—'of occultism'.

Man's unconscious... contains all the patterns of life and behaviour inherited from his ancestors, so that every human child, prior to consciousness, is possessed of a potential system of adapted psychic functioning.