This principle illustrates that there are no coincidences; nothing happens by chance. Chance is a name for an unrecognized law. I have seen this explained this way: “There are many planes of causation, but nothing escapes the law,” which is a classy way to say that for every spell outcome there is a prior action, or cause.
What we send out energetically or through spellwork, be it positive or baneful, will ripple out and return to our own personal world in some way, shape, or form. For every action, there is a reaction. Again, nothing escapes the principle of cause and effect.
