In his book Archetypes, Carl Gustav Jung introduces the concept of the “shadow”.
This is everything that one would consider unacceptable about oneself – stupidly, that is exactly what one is. The “shadow” is therefore one’s own dark side. It would exist on the one hand as an archetypal part of the individual subconscious, on the other hand as one of the collective. (There would be finally many fairy tales and myths, in which a shadow would occur.)
One should not kill off one’s own dark side, but integrate it into the overall personality.
There is also a “white shadow”, which is good in itself, but unfortunately completely undesirable in society.
Robin is particularly fond of shadows in art.