The black cat and the power of symbols
"Symbol" - Word Meaning
The Greek word symbolon means: identification mark, distinguishing feature, and also proof, contract, identity card, password, or Code. With the last two meanings, one enters a realm of "spiritual obligation" or "right of access" and thus enters the dim space of magic.
The magical effect of the symbols
For thousands of years, people have attributed a magical effect to symbols. C.G. Jung wrote: "The symbol has a suggestive, persuasive effect and at the same time expresses the content of the conviction." 
Messages from the unconscious
The magical effect of symbols comes from the fact that they speak the language of the unconscious (see The Conscious and the Unconscious). This language is absorbed by the body, while the mind likes to dismiss the images as unrealistic "nonsense" (see The Language of Images and the Rational Mind).
C.G. Jung called important symbols and generally accepted ideas that are shared by several people ARCHETYPES. Examples are the HERO, the KING, the FATHER, the VIRGIN, CHRIST but also abstract concepts such as GOD, WHOLENESS or SENSE.