If we analyze the principles of thought on which magic is based, they will probably be found to resolve themselves into two: first, that like produces like, or that an effect resembles its cause;
and, second, that things which have once been in contact with each other continue to act on each other at a distance after the physical contact has been severed.
The former principle may be called the Law of Similarity
, the latter the Law of Contact or Contagion
. From the first of these principles, namely the Law of Similarity, the magician infers that he can produce any effect he desires merely by imitating it
: from the second he infers that whatever he does to a material object will affect equally the person with whom the object was once in contact
, whether it formed part of his body or not