On the path of self-realization, especially during processing, sooner or later a practitioner must confront his shadow. In contemporary psychotherapy K.G. Jung was the first to introduce this term and many systems of humanistic and transpersonal psychology took it over from him. So today it is widely accepted.
However, a long time before Jung some thinkers knew about shadow under other terms. More important, they knew about the necessity of integration of fragmented parts of being suppressed into the shadow if one wanted to attain the wholeness of own being. In the hermetism of the 20th century this was called the Guardian of the Threshold and it was considered to lurk in the darkened zones of the being, contained in a kind of psychological cellar. There are interwoven fragmented parts, suppressed sub personalities, rejected aspects, archetypal pictures, long-forgotten childish fears, unacceptable incestuous desires and deep hatred and animosities. Wanting to attain their own goals, each of those parts fights for the attention of the person, no matter how unacceptable for the conscious “I” those goals may be.
Seeing the shadow is a slippery ground, because we have a tendency to ignore its most unpleasant components. Some time ago Zivorad Mihajlovic-Slavinski created the Magical Mirror, a practical method for integration of the shadow into the wholeness of the being. It is very simple. It is one application of DP-4.