קסם סימפתטי הוא סוג של קסם המבוסס על דימיון. אפשר למצוא את הרעיונות בשלב מאוד מוקדם בהתפתחות המיסטית (למשל, as above, so below מופיע כבר בטבלה של הרמס), אבל הוא מנוסח בשם זה אצל פרייזר:

"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."